Methods and devices for treatment of vascular defects

ABSTRACT

Devices for treatment of a patient&#39;s vasculature are described. The device includes a first hub, a second hub, a support structure including a plurality of struts disposed between the first hub and the second hub, and a layer of material disposed over the plurality of struts. The support structure has a low profile, radially constrained state with an elongated tubular configuration suitable for delivery from a microcatheter. The support structure also has an expanded state, a smooth outer surface, and has an axially shortened configuration relative to the radially constrained state. The layer of material may be made from acrylic, silk, silicone, polyvinyl alcohol, polypropylene, polyester, PolyEtherEther Ketone (PEEK), polytetrafluoroethylene (PTFE), polycarbonate urethane (PCU), or polyurethane (PU). The support structure may be formed from a slotted tubular member.

RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 14/044,349, filedOct. 2, 2013, which is a continuation of U.S. application Ser. No.13/794,473, filed Mar. 11, 2013, now abandoned, which is a continuationof U.S. application Ser. No. 13/415,676, filed Mar. 8, 2012, nowabandoned, which is a continuation of U.S. National Phase patentapplication Ser. No. 12/602,997, filed on Oct. 8, 2010, entitled“METHODS AND DEVICES FOR TREATMENT OF VASCULAR DEFECTS,” naming Brian J.Cox et al. as inventors, and designated by attorney docket numberSMI-0103-US, which claims priority from international patent applicationnumber PCT/US2008/065694, filed on Jun. 3, 2008, entitled “Methods andDevices for Treatment of Vascular Defects,” naming Brian J. Cox et al.as inventors, and designated by attorney docket number SMI-0103-PC, U.S.Provisional Patent Application Ser. No. 60/941,916, filed Jun. 4, 2007,entitled “Apparatus and Methods for Positioning and Delivery ofEndoluminal Medical Devices,” naming Brian J. Cox et al. as inventors,and designated by attorney docket number SMI-0100-PV, U.S. ProvisionalPatent Application Ser. No. 60/941,928, filed on Jun. 4, 2007, entitled“Method and Apparatus for Treatment of a Vascular Defect,” naming BrianJ. Cox et al. as inventors, and designated by attorney docket numberSMI-0101-PV, U.S. Provisional Patent Application Ser. No. 60/948,683,filed on Jul. 9, 2007, entitled “Vascular Occlusion Devices,” namingBrian J. Cox et al. as inventors, and designated by attorney docketnumber SMI-0102-PV, U.S. Provisional Patent Application Ser. No.60/971,366, filed on Sep. 11, 2007, entitled “Method and Apparatus forTreatment of a Vascular Defect,” naming Dean Schaefer et al. asinventors, and designated by attorney docket number SMI-0103-PV, andU.S. Provisional Patent Application Ser. No. 61/044,822, filed on Apr.14, 2008, entitled “Methods and Devices for Treatment of VascularDefects,” naming Brian J. Cox et al. as inventors, and designated byattorney docket number SMI-0103-PV2, which are all incorporated byreference herein in their entirety.

FIELD OF THE INVENTION

Generally, embodiments of devices and methods herein are directed toblocking a flow of fluid through a tubular vessel or into a smallinterior chamber of a saccular cavity within a mammalian body. Morespecifically, embodiments herein are directed to devices and methods fortreatment of a vascular defect of a patient including some embodimentsdirected specifically to the treatment of cerebral aneurysms ofpatients.

BACKGROUND

The mammalian circulatory system is comprised of a heart, which acts asa pump, and a system of blood vessels which transport the blood tovarious points in the body. Due to the force exerted by the flowingblood on the blood vessel the blood vessels may develop a variety ofvascular defects. One common vascular defect known as an aneurysmresults from the abnormal widening of the blood vessel. Typically,vascular aneurysms are formed as a result of the weakening of the wallof a blood vessel and subsequent ballooning and expansion of the vesselwall. If, for example, an aneurysm is present within an artery of thebrain, and the aneurysm should burst with resulting cranialhemorrhaging, death could occur.

Surgical techniques for the treatment of cerebral aneurysms typicallyinvolve a craniotomy requiring creation of an opening in the skull ofthe patient through which the surgeon can insert instruments to operatedirectly on the patient's brain. For some surgical approaches, the brainmust be retracted to expose the parent blood vessel from which theaneurysm arises. Once access to the aneurysm is gained, the surgeonplaces a clip across the neck of the aneurysm thereby preventingarterial blood from entering the aneurysm. Upon correct placement of theclip the aneurysm will be obliterated in a matter of minutes. Surgicaltechniques may be effective treatment for many aneurysms. Unfortunately,surgical techniques for treating these conditions include major surgeryprocedures which often require extended periods of time under anesthesiainvolving high risk to the patient. Such procedures thus require thatthe patient be in generally good physical condition in order to be acandidate for such procedures.

Various alternative and less invasive procedures have been used to treatcerebral aneurysms without resorting to major surgery. Some suchprocedures involve the delivery of embolic or filling materials into ananeurysm. The delivery of such vaso-occlusion devices or materials maybe used to promote hemostasis or fill an aneurysm cavity entirely.Vaso-occlusion devices may be placed within the vasculature of the humanbody, typically via a catheter, either to block the flow of bloodthrough a vessel with an aneurysm through the formation of an embolus orto form such an embolus within an aneurysm stemming from the vessel. Avariety of implantable, coil-type vaso-occlusion devices is known. Thecoils of such devices may themselves be formed into a secondary coilshape, or any of a variety of more complex secondary shapes.Vaso-occlusive coils are commonly used to treat cerebral aneurysms butsuffer from several limitations including poor packing density,compaction due to hydrodynamic pressure from blood flow, poor stabilityin wide-necked aneurysms and complexity and difficulty in the deploymentthereof as most aneurysm treatments with this approach require thedeployment of multiple coils.

Another approach to treating aneurysms without surgery involves theplacement of sleeves or stents into the vessel and across the regionwhere the aneurysm occurs. Such devices maintain blood flow through thevessel while reducing blood pressure applied to the Interior of theaneurysm. Certain types of stents are expanded to the proper size byinflating a balloon catheter, referred to as balloon expandable stents,while other stents are designed to elastically expand in aself-expanding manner. Some stents are covered typically with a sleeveof polymeric material called a graft to form a stent-graft. Stents andstent-grafts are generally delivered to a preselected position adjacenta vascular defect through a delivery catheter. In the treatment ofcerebral aneurysms, covered stents or stent-grafts have seen verylimited use due to the likelihood of inadvertent occlusion of smallperforator vessels that may be near the vascular defect being treated.

In addition, current uncovered stents are generally not sufficient as astand-alone treatment. In order for stents to fit through themicrocatheters used in small cerebral blood vessels, their density isusually reduced such that when expanded there is only a small amount ofstent structure bridging the aneurysm neck. Thus, they do not blockenough flow to cause clotting of the blood in the aneurysm and are thusgenerally used in combination with vaso-occlusive devices, such as thecoils discussed above, to achieve aneurysm occlusion.

A number of aneurysm neck bridging devices with defect spanning portionsor regions have been attempted; however, none of these devices has had asignificant measure of clinical success or usage. A major limitation intheir adoption and clinical usefulness is the inability to position thedefect spanning portion to assure coverage of the neck. Existing stentdelivery systems that are neurovascular compatible (i.e. deliverablethrough a microcatheter and highly flexible) do not have the necessaryrotational positioning capability. Another limitation of many aneurysmbridging devices described in the prior art is the poor flexibility.Cerebral blood vessels are tortuous and a high degree of flexibility isrequired for effective delivery to most aneurysm locations in the brain.

What has been needed are devices and methods for delivery and use insmall and tortuous blood vessels that can substantially block the flowof blood into an aneurysm, such as a cerebral aneurysm, with a decreasedrisk of inadvertent aneurysm rupture or blood vessel wall damage. Inaddition, what has been needed are methods and devices suitable forblocking blood flow in cerebral aneurysms over an extended period oftime without a significant risk of deformation, compaction ordislocation.

SUMMARY

Some embodiments of a device for treatment of a patient's vasculatureinclude an expandable body support structure. The expandable bodysupport structure may include a low profile radially constrained statewith an elongated tubular configuration that includes a first end, asecond end, a longitudinal axis and elongate flexible struts disposedsubstantially parallel to each other with first ends thereof secured toa first ring and second ends thereof secured to a second ring. The firstand second rings may be disposed substantially concentric to thelongitudinal axis, and a middle portion of the expandable body may havea first transverse dimension with a low profile suitable for deliveryfrom a microcatheter. The expandable body may also have an expandedrelaxed state having an axially shortened configuration relative to theconstrained state with the first ring disposed adjacent the second ring,both rings substantially concentric to the longitudinal axis and eachstrut forming a smooth arc between the first and second rings with areverse bend at each end such that the arc of each strut extends axiallybeyond each respective ring and such that the middle portion has asecond transverse dimension substantially greater than the firsttransverse dimension. Each strut may be configured to independently flexradially with respect to the longitudinal axis of the expandable body. Apermeable layer defect spanning structure is disposed at and conforms toa profile of a second end of the expandable body when in the expandedrelaxed state.

Some embodiments of a device for treatment of a patients vasculatureinclude an expandable body support structure having a low profileradially constrained state with a first end, a second end, an elongatedtubular configuration having a longitudinal axis, elongate flexiblestruts connected at intersections between the first end and second endforming a plurality of open cells between struts in a middle portion ofthe expandable body, and a first transverse dimension suitable fordelivery from a microcatheter configured for navigation in cerebralvasculature. The expandable body also has an expanded relaxed state witha tubular configuration including a second transverse dimensionsubstantially greater than the first transverse dimension of the tubularconfiguration of the constrained state. A permeable layer may span atleast one cell between struts of the expandable body. A permeable layermay also span a portion of a cell between struts.

Some embodiments of a device for treatment of a patient's vasculatureinclude an expandable body support structure having a low profileradially constrained state with an elongated tubular configuration thatincludes a first end, a second end, a longitudinal axis and elongateflexible struts disposed substantially parallel to each other with firstends thereof secured relative to each other. A middle portion of theexpandable body may have a first transverse dimension with a low profilesuitable for delivery from a microcatheter. The expandable body also hasan expanded relaxed state with an axially shortened configurationrelative to the constrained state with each strut forming a smooth aresuch that the arc of each strut extends axially beyond the firsttransverse dimension and such that the middle portion has a secondtransverse dimension substantially greater than the first transversedimension. Each strut may be configured to Independently flex in aradial orientation with respect to the longitudinal axis of theexpandable body. A defect spanning structure comprising a permeablelayer is disposed at and conforms to a profile of a second end of theexpandable body when in the expanded relaxed state.

Some embodiments of a device for treatment of a patient's vasculatureinclude an expandable body support structure having a low profileradially constrained state with a first end, a second end, an elongatedtubular configuration having a longitudinal axis, elongate flexiblestruts connected at intersections between the first end and second endforming a plurality of open cells between struts in a middle portion ofthe expandable body. The expandable body has a first transversedimension which is suitable for delivery from a microcatheter and whichis configured for navigation in cerebral vasculature. The expandablebody also has an expanded relaxed state with a tubular configurationincluding a second transverse dimension substantially greater than thefirst transverse dimension of the tubular configuration of theconstrained state. A permeable layer is secured to the expandable bodyand may be configured to cover an aneurysm opening and which is axiallydisplaced from the expandable body support structure and orientedsubstantially perpendicular to the longitudinal axis of the expandablebody support structure when in the expanded relaxed state.

Some embodiments of a device for treatment of a patients vasculatureinclude an expandable body support structure having a low profileradially constrained state with an elongated tubular configuration thatincludes a first end, a second end, a longitudinal axis and elongateflexible struts disposed substantially parallel to each other with firstends thereof secured to a first ring and second ends thereof securedrelative to each other. The first ring may be disposed substantiallyconcentric to the longitudinal axis, and a middle portion of theexpandable body may have a first transverse dimension with a low profilesuitable for delivery from a microcatheter. The expandable body also hasan expanded relaxed state having an axially shortened configurationrelative to the constrained state with the second ends everted within aradially expanded middle portion and disposed adjacent the first ringsubstantially concentric to the longitudinal axis. Each strut may form asmooth arc between the first and second ends such that the arc of eachstrut extends axially beyond the first transverse dimension and suchthat the middle portion has a second transverse dimension substantiallygreater than the first transverse dimension. Each strut may also beconfigured to independently flex radially with respect to thelongitudinal axis of the expandable body. A permeable layer defectspanning structure is disposed at and conforms to a profile of the firstend of the expandable body when in the expanded relaxed state.

Some embodiments of a method of treating a vascular defect includeproviding a vascular defect treatment device having a support structurewith an expandable body and a defect spanning structure that includes aplurality of microfibers that are substantially parallel to each otherwhen the support structure is in an expanded relaxed state. A deliverysystem may be advanced to a position adjacent a vascular defect to betreated and the device positioned inside the vascular defect.Thereafter, the device may be deployed such that the expandable bodyself-expands and the defect spanning structure covers at least a portionof the defect opening or neck.

Some embodiments of a method of treating a vascular defect includeproviding a vascular defect treatment device having a support structurewith an expandable body and a defect spanning structure that includes aplurality of microfibers that are substantially parallel to each otherwhen the support structure is in an expanded relaxed state. A deliverysystem may be advanced to a position adjacent a vascular defect to betreated and the device positioned adjacent the vascular defect. Thedevice may then be deployed such that the expandable body self-expandsadjacent the vascular defect and the defect spanning structure covers atleast a portion of the defect opening or neck.

Some embodiments of a method for treating a vascular defect includeproviding a device for treatment of a patient's vasculature having asupport structure including a substantially hollow expandable body and adefect spanning structure that includes a permeable membrane disposed onthe expandable body. A delivery system including a microcatheter may beadvanced into a patient's body to a position adjacent a vascular defectto be treated. The device may then be rotationally positioned about alongitudinal axis of the catheter while the device is disposed in aradially constrained state at a distal end of the catheter. Therotational positioning may be carried out from a proximal end of thecatheter with an elongate actuator releasably secured to the device. Thedevice may be positioned until the defect spanning structure of thedevice is substantially aligned in a circumferential orientation withthe vascular defect to be treated. The device may then be deployed so asto allow the device to achieve an expanded relaxed state with thepermeable membrane at least partially covering the vascular defect so asto isolate the defect from the patient's vasculature.

Some embodiments of a method of treating a patient's vasculature includeproviding a device for treatment of a patient's vasculature that has asupport structure with a self-expanding expandable body and a defectspanning structure has a permeable layer disposed on the expandablebody. The device may be deployed at the confluence of three vessels ofthe patient's vasculature that form a bifurcation such that the defectspanning structure substantially covers the neck of a terminal aneurysmand one or more struts of the support structure span or cross each ofthe three vessels.

Some embodiments of a method of making a device for treatment of apatient's vasculature include forming a plurality of strut members intoa substantially tubular member having a distal end and a proximal endwherein the strut members extend parallel to each other and alongitudinal axis of the tubular member in a cylindrical array. Thestrut members may also be secured to respective proximal and distal endsof the tubular structure. The struts are then shaped to form a globularsupport structure with a middle portion of the struts extending radiallyoutward in a curving arc. For some embodiments, such a shape may be heatset or otherwise fixed. A permeable layer including a porous membrane,mesh or microfiber matrix that is less than about 50 microns thick maythen be formed and secured to at least a portion of the supportstructure to form a defect spanning structure.

These features of embodiments will become more apparent from thefollowing detailed description when taken in conjunction with theaccompanying exemplary drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a terminal aneurysm.

FIG. 2 is a sectional view of an aneurysm.

FIG. 3 is a perspective view of an embodiment of a laser cut tube in atubular configuration prior to expansion and heat setting.

FIG. 4 illustrates an embodiment of a portion of a permeable layer for adefect spanning structure of a device for treatment of a patient'svasculature.

FIG. 5 illustrates an embodiment of a portion of a permeable layer for adefect spanning structure of a device for treatment of a patient'svasculature.

FIG. 6 illustrates an embodiment of a portion of a permeable layer for adefect spanning structure of a device for treatment of a patient'svasculature.

FIG. 7 shows a defect spanning structure in the form of a hemisphericaldome with flat sides.

FIG. 8 is a perspective view of a distal or first end portion of a lasercut tube showing holes formed therein for securing microfibers or anyother suitable filament.

FIG. 9 shows a section of a support structure of a device for treatmentof a patient's vasculature illustrating microfibers spanning an openingin the support structure.

FIG. 10 is an elevation view in partial section of a junction between anend of a microfiber and a strut of a support structure of a device fortreatment of a patient's vasculature.

FIG. 11 is a perspective view of a proximal end of a device fortreatment of a patients vasculature having microfiber elements spanninggaps between a proximal portion of the support structure and with adistal portion of a microcatheter accessing an interior volume of thedevice.

FIG. 12 is a view of an embodiment of electrospun microfiber.

FIG. 13 is an elevation view in partial section of an embodiment of adevice for treatment of a patient's vasculature deployed within ananeurysm.

FIG. 14 is an elevation view in partial section of a proximal portion ofan embodiment of a device for treatment of a patient's vasculaturedeployed within an aneurysm.

FIG. 15 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patient's vasculature deployed adjacent theaneurysm.

FIG. 16 shows a view in longitudinal section of an aneurysm with anembodiment of a device for treatment of a patient's vasculature deployedadjacent the aneurysm.

FIG. 17 shows the device of FIG. 16 disposed within a microcatheter in acollapsed radially constrained state.

FIG. 18 illustrates an elevation view of an embodiment of a device fortreatment of a patient's vasculature.

FIG. 19 shows the device of FIG. 18 disposed in a microcatheter in acollapsed radially constrained state.

FIG. 20 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patient's vasculature deployed adjacent theaneurysm.

FIG. 21 shows the device of FIG. 20 disposed within a microcatheter in acollapsed radially constrained state.

FIG. 22 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patient's vasculature deployed adjacent theaneurysm.

FIG. 22A shows the device of FIG. 22 disposed within a microcatheter ina collapsed radially constrained state.

FIG. 23 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patient's vasculature deployed adjacent theaneurysm.

FIG. 24 shows the device of FIG. 23 disposed within a microcatheter in acollapsed radially constrained state.

FIG. 25 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patients vasculature deployed adjacent theaneurysm.

FIG. 26 shows the device of FIG. 25 disposed within a microcatheter in acollapsed radially constrained state.

FIG. 27 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patient's vasculature deployed adjacent theaneurysm.

FIG. 28 shows a view in longitudinal section of an aneurysm with anembodiment of a device for treatment of a patient's vasculature deployedadjacent the aneurysm.

FIG. 29 illustrates an elevation view of an embodiment of a device fortreatment of a patients vasculature.

FIG. 30 shows the device of FIG. 10 disposed within a microcatheter in acollapsed radially constrained state.

FIG. 31 is a sectional view of an aneurysm with an embodiment of adevice for treatment of a patients vasculature deployed within theaneurysm.

FIG. 32 is a sectional view of a terminal aneurysm with an embodiment ofa device for treatment of a patients vasculature deployed within theaneurysm.

FIG. 33 is a sectional view of an aneurysm with an embodiment of adevice for treatment of a patient's vasculature deployed within theaneurysm.

FIG. 34 is an elevation view of an outline of an embodiment of a devicefor treatment of a patient's vasculature having a recessed detachmenthub.

FIG. 35 is a perspective view of a heat set inverted or everted globesupport structure of a device for treatment of a patient's vasculature.

FIG. 36 is a proximal end view of the expandable body support structureof FIG. 35.

FIG. 37 shows a sectional view of an embodiment of a device fortreatment of a patients vasculature deployed in a vascular defect.

FIG. 38 shows the device of FIG. 37 disposed within a microcatheter in acollapsed radially constrained state.

FIG. 39 is an elevation view of a laser cut tube prior to heat settingand formation of a support structure embodiment for a device fortreatment of a patient's vasculature.

FIG. 40 is an elevation view of the laser cut tube of FIG. 39 in apartially expanded state for heat setting.

FIG. 41 is an elevation view of the laser cut tube of FIG. 39 with adistal end of the tube inverted or everted into the expanded globestructure of the laser cut tube for heat setting.

FIG. 42 is an elevation view of the laser cut tube of FIG. 39 with thedistal end of the tube further inverted or everted into the globestructure of the laser cut tube for heat setting with the distal end ofthe tube adjacent the proximal end of the laser cut tube.

FIG. 43 is an elevation view of an embodiment of a device for treatmentof a patient's vasculature in a relaxed expanded state disposed in avascular defect of a patient.

FIG. 44 shows the device of FIG. 43 disposed within an inner lumen of amicrocatheter embodiment in a collapsed radially constrained state.

FIG. 45 is an elevation view of an embodiment of a device for treatmentof a patient's vasculature.

FIG. 46 is a sectional view of the device of FIG. 45 taken along lines46-46 of FIG. 45.

FIG. 47 shows a bottom perspective view of the device for treatment of apatient's vasculature of FIG. 45.

FIG. 48 is a transverse cross sectional view of a circular array ofstrut elements in a collapsed restrained state.

FIG. 49 is an elevation view of a laser cut tube prior to heat settingand formation of an embodiment of a support structure for a device fortreatment of a patient's vasculature.

FIG. 50 is an elevation view of elongate strut elements of the laser cuttube of FIG. 49 disposed over a shaping mandrel.

FIG. 51 is an elevation view of the laser cut tube of FIG. 49 which isheat set with first and second ends of the tube axially collapsedtowards each other into an everted globe like structure.

FIG. 52 is an enlarged view of a proximal portion of a strut element ofthe heat set support structure of FIG. 51.

FIG. 53 shows an embodiment of a mandrel that may be used for formingembodiments of defect spanning structures.

FIG. 54 shows a perspective view of a permeable membrane of a defectspanning structure embodiment.

FIG. 55 illustrates a schematic view of a vapor deposition process.

FIG. 56 shows a cross sectional view of a portion of a junction betweenan embodiment of a defect spanning structure and strut of a supportstructure.

FIG. 57 illustrates an embodiment of a defect spanning structure flatpattern.

FIG. 58 illustrates a perspective view broken away of an embodiment of astrut engaged with a defect spanning structure membrane.

FIG. 59 is a perspective view of a segment of a strut member of asupport structure embodiment.

FIGS. 60-63 show a deployment sequence of a device for treatment of apatient's vasculature.

FIG. 64 shows a perspective view of a delivery catheter embodiment.

FIG. 65 illustrates a delivery catheter embodiment disposed within avascular lumen of a patient.

FIG. 66 shows an embodiment of a torque transfer mechanism.

FIG. 67 shows an elevation view of a distal portion of a deliverycatheter embodiment.

FIG. 68 is an elevation view of a proximal portion of a deliverycatheter embodiment.

FIG. 69 is an elevation view of a rotation mechanism of a deliverycatheter embodiment.

FIG. 70 is an elevation view in partial section of a distal portion of adelivery catheter embodiment.

FIG. 70A is a transverse cross section of the embodiment of FIG. 70taken along lines 70A-70A of FIG. 70.

FIG. 71 is an elevation view in partial section of a distal portion of adelivery catheter embodiment.

FIG. 72 is a perspective view in partial section of a distal portion ofa delivery catheter embodiment.

DETAILED DESCRIPTION

As discussed above, there has been a need for devices and methods forthe efficacious treatment of vascular defects that are suitable forminimally invasive deployment within a patient's vasculature, andparticularly, within the cerebral vasculature of a patient. For suchembodiments to be safely and effectively delivered to a desiredtreatment site and effectively deployed, the device embodiments may beconfigured for collapse to a low profile state with a transversedimension suitable for delivery through a microcatheter and deploymentfrom a distal end thereof. In addition, there has been a need for suchdevices that will maintain a clinically effective configuration withsufficient mechanical integrity once deployed so as to withstand thedynamic forces within a patient's vasculature over time.

Apparatus and method embodiments for the treatment of vascular defectsincluding aneurysms and, more specifically, cerebral aneurysms, arediscussed herein. Some embodiments are particularly useful for thetreatment of cerebral aneurysms by reconstructing a vascular wall so asto wholly or partially isolate a vascular defect from a patient's bloodflow. Some device embodiments include an endoluminal implant device fortreatment of a patient's vasculature with a support structure and adefect spanning structure. Some embodiments of a device may beconfigured to be placed in a blood vessel adjacent a vascular defect tofacilitate reconstruction, bridging of a vessel wall or both in order totreat the vascular defect.

For some of these embodiments, the support structure which may serve toanchor or fix the defect spanning structure in a clinically beneficialposition may be secured to the patient's vasculature in the patient'svessel adjacent the vascular defect. In other embodiments, the supportstructure may be disposed in whole or in part within the vascular defectin order to anchor or fix the device with respect to the vascularstructure. In either of these embodiments, the defect spanningstructure, which is secured to the support structure, may be configuredto span an opening, neck or other portion of the vascular defect inorder to isolate the vascular defect, or a portion thereof, from thepatient's nominal vascular system in order allow the defect to heal orto otherwise minimize the risk of the defect to the patient's health.

For some or all of the embodiments of devices for treatment of apatient's vasculature discussed herein, the defect spanning structuremay include a membrane that allows some perfusion of blood through themembrane. The porosity of the membrane of the defect spanning structuremay be configured to sufficiently isolate the vascular defect so as topromote healing and isolation of the defect, but allow sufficient flowthrough the membrane so as to reduce or otherwise minimize themechanical force exerted on the membrane the dynamic flow of blood orother fluids within the vasculature against the membrane. Membraneembodiments may take on a variety of configurations to provide a desiredclinical effect, including porous membranes, perforated membranes,membranes having multiple sizes of perforations, membranes havingmultiple layers, multiple layers of membranes, membranes havingpredetermined a porosity ratio and pore size, membranes configured forelution of bioactive agents as well as other configurations or anycombination of these features.

Some device embodiments may also include a sealing member in the form ofan elongate deformable element that is configured to conform to anirregular surface and form a seal between the defect spanning structureand the patient's vascular tissue. Such sealing members may be acontinuous elongate element, such as with an annular ring, that mayserve to prevent undesirable blood flow or flow of other fluids betweenthe edges or periphery of the defect spanning structure and the tissueadjacent the defect spanning structure.

Some embodiments of devices for the treatment of a patient's vasculaturediscussed herein may be directed specifically to the treatment ofspecific types of defects of a patient's vasculature. For example,referring to FIG. 1, an aneurysm 10 commonly referred to as a terminalaneurysm is shown in section. Terminal aneurysms occur typically atbifurcations in a patients vasculature where blood flow from a supplyvessel splits into two or more branch vessels directed away from eachother. The main flow of blood from the supply vessel 12, such as abasilar artery, sometimes impinges on the vessel where the vesseldiverges and where the aneurysm sack forms. Terminal aneurysms may havea well defined neck structure where the profile of the aneurysm narrowsadjacent the nominal vessel profile, but other terminal aneurysmembodiments may have a less defined neck structure or no neck structure.FIG. 2 illustrates a typical berry type aneurysm 14 in section where aportion of a wall of a nominal vessel section 16 weakens and expandsinto a sack like structure ballooning away from the nominal vesselsurface and profile. Some berry type aneurysms may have a well definedneck structure as shown in FIG. 2, but others may have a less definedneck structure or none at all.

Embodiments of devices and methods for treatment of a patient'svasculature discussed herein may include a defect spanning structureconfigured to span all or a portion of a vascular defect in order toisolate the defect and promote healing, lessen or eliminate the risk orrupture or both. The defect spanning structure embodiments may include avariety of materials and configurations in order to provide a desiredclinical result.

The defect spanning portion may be formed of a sheet material or fabricthat is attached to the one or more surfaces of the support structure.Alternatively, the defect spanning portion may be fabricated as anintegral part of the overall structure. These integral members may becut by laser, photochemical etching or electrical discharge machining(EDM). In some embodiments, the defect spanning strut members 18 have atleast one portion that has a wave-like shape as shown in the supportstructure embodiment 20 in FIG. 3. For some embodiments, material may beattached to the structure such that it substantially reduces the size ofthe fenestrations or cells and thus reduces the porosity in that area.For example, coatings, filaments, fibers, wires, struts, ribbons, sheetor fabric may be connected to portions of the structure to create smallfenestrations or cells and thus higher density of the defect spanningportion (as shown in FIG. 18 below). Active materials such as aresponsive hydrogel may be attached or otherwise incorporated intodefect spanning structure embodiments such that it swells upon contactwith liquids over time to reduce the porosity of the spanning structure.The defect spanning structure may have a microporous or microtexturedsurface. The microtextured surface may comprise pores, holes, voids,protrusions or other microfeatures. The microfeatures may be less thanabout 150 microns in diameter, height and/or depth.

Occlusive mesh and defect spanning structure embodiments generally mayhave a low volume to allow for the device to be collapsed into a smallcatheter for delivery. For some embodiments, the total volume of theocclusive membrane material may be less than about 5 mm3. For someembodiments, the total volume of the membrane material may be between0.5 and 4 mm3. Defect spanning structure embodiments may be formed ofstrands of material and may be woven, braided or knitted as is known inthe art of textile vascular grafts. Optionally, the device may includefibers or strands that are woven, braided or knitted as is known in theart of textile vascular grafts.

Defect spanning structure embodiments may be thinner than typicaltextiles used in vascular implants. The thickness of the defect spanningstructure may be less than about 50 microns. In some embodiments, thedefect spanning structure may be between about 2 and 10 microns thick. Athin defect spanning structure may allow it to be packed within thelumen of the support structure when collapsed and in a substantiallycylindrical form for delivery through a catheter. The defect spanningstructure may be porous and may be highly permeable to liquids. Incontrast to most vascular prosthesis fabrics or grafts which typicallyhave a water permeability below 2,000 ml/min/cm2 when measured at apressure of 120 mmHg, the defect spanning structure may have a waterpermeability greater than about 2,000 ml/min/cm2 and may be betweenabout 2,000 and 10,000 ml/min/cm2 when measured at a pressure of 120mmHg. In some embodiments, the defect spanning structure is a porousthin membranous film.

In some embodiments, the pores may be formed in an array such as thosepores formed in the membrane embodiments shown in FIGS. 4 and 5. FIG. 4shows a defect spanning structure membrane 22 having regularly spacedholes 24 having a substantially round shape through the membrane. FIG. 5shows a defect spanning structure membrane 26 having a plurality ofregularly spaced holes 28 having a substantially diamond shape

For some embodiments, the distance between the pores or web thicknessmay be less than about 100 microns and may be between about 20 and 60microns. The pores may be in a variety of shapes Including round, ovoid,square, and diamond. In some embodiments the defect spanning structure30 may have macropores 32 and micropores 34 formed in the same membrane30 as shown in FIG. 6. The macropores 32 may provide the majority of thedesired permeability while the micropores 34 may provide improvedhealing and/or tissue ingrowth of the surfaces between the macropores32. For some embodiments, the macropores 32 may be between about 100microns and 500 microns in size (e.g., diameter). For some embodiments,the micropores 34 may be between about 10 microns and 100 microns insize. The macropores may be formed by laser perforation, mechanicalperforation, surface treatments or any other suitable method during orafter film formation. The micropores may be formed by various meansknown in the art of micropore formation including but not limited to theuse of a porosigen during film formation, laser perforation, foamingprocesses, phase inversion processes or surface treatments during orafter film formation.

In some embodiments, the defect spanning structure may be formed in agenerally three dimensional curved shape such as a hemisphere orsubstantially hemispheric shape. A three dimensional shape that may bedesirable for some embodiments of permeable membranes of defect spanningstructures may include a hemispherical dome 36 with flat or segmentedsides without compound curvature wherein a membrane structure may extenddirectly or substantially directly between adjacent strut members asshown in FIG. 7. A membrane structure 36 having flat sides may provideminimization of extra membrane or spanning structure material that maybe loose and buckle inward forming a path for blood to flow into ananeurysm around the device. For some embodiments, the membrane or defectspanning material may be stretched taught between adjacent strut memberswhen a device is in an expanded deployed state.

For some embodiments, a portion of the proximal end opening area of thesupport structure may be covered or spanned by the defect spanningstructure. The defect spanning structure for some embodiments may behighly porous having greater than about 60% porosity. In someembodiments, the area of the proximal end of a support structure coveredby the defect spanning structure may be between about 10% and 40%. Thedefect spanning structure may be constructed by formation of a porousmembrane or a network or array of small filamentary elements, fibers,wires or threads (hereinafter referred to as microfibers). Themicrofibers may have a thickness or diameter less than about 0.040 mm.In one embodiment, the thickness or diameter of the microfibers isbetween 0.015 and 0.030 mm.

In some embodiments, at least a portion of some struts of a supportstructure 37 have a plurality of holes or microholes 38 for attachmentof the defect spanning structure as shown in FIG. 8. In someembodiments, there may be two rows of holes in a proximal portion ofsome struts 40 of the support structure 37. The holes 38 may be madesuch that they define a lumen that is perpendicular to the strut and thesupport structure 37. Thus the axis of the hole is radial to the supportstructure. Alternatively, the holes 38 may be tangential to thestructure. For some embodiments, detachments loops 42 may be formed atan end, such as a first or proximal end of a support structure, such assupport structure 37. In some embodiments, a defect spanning structuremay be formed by a plurality of microfibers 44 that are threaded throughthe holes of one or more support structure struts 46 as shown in FIG. 9.The microfibers may span from strut to strut 46 in a substantiallystraight line or have a curved shape. The fibers 44 may be configured soas to substantially align with the surface or shape defined by thesupport structure. A gap between microfibers, as indicated by arrows 48in FIG. 9, may be selected to generate a desired level of porosity ofthe defect spanning structure formed by the microfibers 44. Themicrofibers 44 may be attached to the structure by knots, adhesives or asmall anchor element or member 50 that is attached to an end of amicrofiber 44 and pulled against a hole 38 as shown in FIG. 10. For someembodiments, the fibers may have lengths configured to span a gapbetween struts and be held taught under tension when the supportstructure is in a relaxed deployed state.

Some of the microfibers may be substantially parallel as they span twostruts. The gaps or slots 48 formed by the openings between two fibersmay be less than about 0.125 mm for some embodiments. With themicrofibers being arranged in a substantially parallel fashion asopposed to a mesh (e.g braid), a guidewire or microcatheter 52 may bemore easily be passed through the openings as shown in FIG. 11. Thisallows for a subsequent treatment such as the delivery of an embolicmaterial and/or devices to fill at least a portion of the space behindthe defect spanning structure. Further, mesh structures typicallyinvolve overlapping of fibers that result in a thicker, more voluminousmembrane.

In some embodiments, the defect spanning structure may include a fabricwhich may be a mesh, network, weave, braid or other fabric constructionof microfibers, wires or filaments. The fabric may be made in a varietyof shapes including round, oval, elliptical. The thickness of the fabricmay be between about 0.025 mm and about 0.25 mm. The individualmicrofibers may range in diameter from about 50 nm to about 50,000 nm(nanometers). In some embodiments, the microfibers may have a diameteror transverse dimension of about 500 nm to about 5,000 nm.

In some embodiments, the microporous structure may be formed by a mesh,matrix or other non-uniform structure of microfibers. For example, anelectrospun mesh may be formed as described herein with pores that areon average between about 25 microns and 100 microns in size.Macroporosity of the mesh may be obtained by casting the fibers on to amacroporous (e.g., mesh) collector. A flow of gas through the collectoror a vacuum may be used to reduce the spanning of the collector poreswith fibers. Alternatively, macropores may be cut, burned or otherwiseformed in a microporous mesh or microfiber matrix after it has beenformed.

Some process embodiments for making microfibers and/or fabric meshesinclude electrospinning. An example of an electrospun fabric 54 is shownin FIG. 12. Processes and materials for electrospinning fabric meshesfor biomedical use are described by Quynh et al. in Electrospinning ofPolymeric Nanofibers for Tissue Engineering Applications: A Review(Tissue Engr 2006; 12(5): 1197-1211, by Sen et al. in U.S. PatentApplication No. 2005/0053782, filed Sep. 2, 2004, titled “Process forForming Polymeric Micro and Nanofibers”, by Laurencin et al. In U.S.Patent Application No. 2005/0112349, filed Sep. 10, 2004, titled“Polymeric Nanofibers for Tissue Engineering and Drug Delivery”, byDevellian et al. in U.S. Patent Application No. 2005/0113868, filed Jun.22, 2004, titled “Device, with Electrospun Fabric, for a PercutaneousTransluminal Procedure, and Methods thereof”, and by Schewe et al. inU.S. Patent Application No. 2007/0144124, filed Dec. 23, 2005, titled“Spun Nanofiber, Medical Devices, and Methods”, all of which areincorporated by reference herein in their entirety.

Some embodiments of electrospun fibers may be derived by charging aliquid typically to 5-30 kV vs. a ground a short distance away, whichleads to charge injection into the liquid from the electrode. The signof the injected charge depends upon the polarity of the electrode; anegative electrode produces a negatively charged liquid. The chargedliquid is attracted to the ground electrode of opposite polarity,forming a so-called Taylor cone at the nozzle tip and, eventually, afiber jet as the electric field strength exceeds the surface tension ofthe solution. Exemplary synthetic materials for producing electrospunfiber for the present invention include polyurethanes, polyimides,polyethers, silicones, polyesters, polyolefins, poly(ethylene-co-vinylalcohol) copolymers from 2-propanol-water solutions and PVA poly(vinylalcohol) fibers. Another class of materials for electroprocessing tomake the compositions for embodiments herein may include extracellularmatrix proteins. Examples include but are not limited to collagen,fibrin, elastin, laminin, and fibronectin.

Defect spanning structure embodiments of devices for treatment of apatient's vasculature may include multiple layers. A first or outerlayer 56 may be attached to a proximal portion of a support structure58. Subsequent or inner layer(s) 60 may be attached distal to theproximal end of the support structure struts as shown in FIG. 13 withsome lower strut portions not shown for clarity of illustration. In someembodiments, the fabric layer or layers are fabricated directly on tothe support structure 58, fusing to each other and/or the supportstructure as they are formed. The first or outer layer 56 may beconstructed from a material with low bioactivity and hemocompatibilityso as to minimize platelet aggregation or attachment and thus thepropensity to form clot and thrombus. Optionally, the outer layer 56 maybe coated or incorporate an antithrombogenic agent such as heparin orother antithrombogenic agents described herein or known in the art. Oneor more inner layers 60 distal to the first layer may be constructed ofmaterials that have greater bioactivity and/or promote clotting and thusenhance the formation of an occlusive mass of clot and device within thevascular defect. Some materials that have been shown to have bioactivityand/or promote clotting include silk, polylactic acid (PLA),polyglycolic acid (PGA), collagen, alginate, fibrin, fibrinogen,fibronectin, Methylcellulose, gelatin, Small Intestinal Submucosa (SIS),poly-N-acetylglucosamine and copolymers or composites thereof.

Device embodiments discussed herein may be coated with various polymersto enhance it performance, fixation and/or biocompatibility. Inaddition, device embodiments may be made of various biomaterials knownin the art of implant devices including but not limited to polymers,metals, biological materials and composites thereof. Device embodimentsmay include metals, polymers, biologic materials and composites thereof.Suitable metals include zirconium-based alloys, cobalt-chrome alloys,nickel-titanium alloys, platinum, tantalum, stainless steel, titanium,gold, and tungsten. Potentially suitable polymers include but are notlimited to acrylics, silk, silicones, polyvinyl alcohol, polypropylene,polyvinyl alcohol, polyesters (e.g., polyethylene terephthalate or PET),PolyEtherEther Ketone (PEEK), polytetrafluoroethylene (PTFE),polycarbonate urethane (PCU) and polyurethane (PU). The device mayinclude a material that degrades or is absorbed or eroded by the body. Abioresorbable (e.g., breaks down and is absorbed by a cell, tissue, orother mechanism within the body) or bioabsorbable (similar tobioresorbable) material may be used. Alternatively, a bioerodable (e.g.,erodes or degrades over time by contact with surrounding tissue fluids,through cellular activity or other physiological degradationmechanisms), biodegradable (e.g., degrades over time by enzymatic orhydrolytic action, or other mechanism in the body), or dissolvablematerial may be employed. Each of these terms is interpreted to beinterchangeable. Potentially suitable bioabsorbable materials includepolylactic acid (PLA), poly(alpha-hydroxy acid) such as poly-L-lactide(PLLA), poly-D-lactide (PDLA), polyglycolide (PGA), polydioxanone,polycaprolactone, polygluconate, polyactic acid-polyethylene oxidecopolymers, modified cellulose, collagen, poly(hydroxybutyrate),polyanhydride, polyphosphoester, poly(amino acids), or related copolymermaterials. An absorbable composite fiber may be made by combining areinforcement fiber made from a copolymer of 18% glycolic acid and 82%lactic acid with a matrix material consisting of a blend of the abovecopolymer with 20% polycaprolactone (PCL). In some embodiments, theratio of polylactide or lactic acid may be between about 65% and 90%.

In any of the device embodiments discussed herein, the defect spanningstructure may be formed at least in part of acrylic, polyurethane,silicone, polypropylene, polyvinyl alcohol, polyesters (e.g.,polyethylene terephthalate or PET), polybutester, and PolyEtherEtherKetone (PEEK). One potentially suitable group of materials includespolyurethanes-based polymers that may include a soft segment and a hardsegment. The segments can be combined as copolymers or as blends. Forexample, polymers with soft segments such as PTMO, polyethylene oxide,polypropylene oxide, polycarbonate, polyolefin, polysiloxane (i.e.polydimethylsiloxane), and other polyether soft segments made fromhigher homologous series of diols may be used. Mixtures of any of thesoft segments may also be used. The soft segments also may have eitheralcohol end groups or amine end groups. The molecular weight of the softsegments may vary from about 500 to about 5,000 g/mole.

A group of materials that may be useful for the defect spanningstructure may include silicone-urethane composites orsiloxane-polyurethane. Examples of polyurethanes containing siloxanesegments include polyether siloxane-polyurethanes, polycarbonatesiloxane-polyurethanes, and siloxane-polyurethane ureas. Specifically,examples of siloxane-polyurethane include polymers such as Elast-Eon(AORTECH BIOMATERIALS, Victoria, Australia); polytetramethyleneoxide(PTMO) and polydimethylsiloxane (PDMS) polyether-based aromaticsiloxane-polyurethanes such as PurSil-10, -20, and -40 TSPU; PTMO andPDMS polyether-based aliphatic siloxane-polyurethanes such as PurSilAL-5 and AL-10 TSPU; aliphatic, hydroxy-terminated polycarbonate andPDMS polycarbonate-based siloxane-polyurethanes such as CarboSil-10,-20, and -40 TSPU (all available from Polymer Technology Group, Inc.,Berkeley, Calif.).

The PurSil, PurSil-AL, and CarboSil polymers are thermoplastic elastomerurethane copolymers containing siloxane in the soft segment, and thepercent siloxane in the copolymer is referred to in the grade name. Forexample, PurSil-10 contains 10% siloxane. These polymers are synthesizedthrough a multi-step bulk synthesis in which PDMS is incorporated intothe polymer soft segment with PTMO (PurSil) or an aliphatichydroxy-terminated polycarbonate (CarboSil). The hard segment consistsof the reaction product of an aromatic diisocyanate, MDI, with a lowmolecular weight glycol chain extender. In the case of PurSil-AL thehard segment is synthesized from an aliphatic diisocyanate. The polymerchains are then terminated with a siloxane or other surface modifyingend group. Siloxane-polyurethanes typically have a relatively low glasstransition temperature, which provides for polymeric materials havingincreased flexibility relative to many conventional materials. Inaddition, the siloxane-polyurethane can exhibit high hydrolytic andoxidative stability, including improved resistance to environmentalstress cracking.

Other examples of siloxane-polyurethanes are disclosed in U.S. PatentApplication Publication No. 2002/0187288 A1, titled “Medical DeviceFormed of Silicone-Polyurethane” filed Jun. 11, 2001, by Lim et al.,which is incorporated herein by reference in its entirety. Anotherpotentially suitable polyurethane based material for the defect spanningstructure may be THORALON™ (THORATEC, Pleasanton, Calif.), as describedby Jayaraman et al. in U.S. Patent Application No. 2002/0065552, filedAug. 20, 2001, titled “Coated Vascular Grafts and Methods of Use”, andby Ward in U.S. Pat. No. 4,675,361, filed Jun. 24, 1983, titled “PolymerSystems Suitable for Blood-Contacting Surfaces of a Biomedical Device,and Methods of Forming”, both of which are incorporated by herein byreference in their entirety. According to these references, THORALON isa polyurethane base polymer (referred to as BPS-215) blended with asiloxane containing surface modifying additive (referred to as SMA-300).Base polymers containing urea linkages may also be used. Theconcentration of the surface modifying additive may be in the range ofabout 0.5% to about 5% by weight of the base polymer. The SMA-300component (THORATEC) is a polyurethane including polydimethysiloxane asa soft segment and the reaction product of diphenylmethane diisocyanate(MDI) and 1,4-butanediol as a hard segment.

Device embodiments discussed herein may include cells and/or otherbiologic material to promote healing. Device embodiments discussedherein may also be constructed to provide the elution or delivery of oneor more beneficial drugs, other bioactive substances or both into theblood or the surrounding tissue. Device embodiments herein may include asurface treatment or coating on a portion, side or all surfaces thatpromotes or inhibits thrombosis, clotting, healing or other embolizationperformance measure. The surface treatment or coating may be asynthetic, biologic or combination thereof. For some embodiments, atleast a portion of an inner surface of the defect spanning structure mayhave a surface treatment or coating made of a biodegradable orbioresorbable material such as a polylactide, polyglycolide or acopolymer thereof. Another surface treatment or coating material whichmay enhance the embolization performance of a device includes apolysaccharide such as an alginate based material. Potentially suitablealginate based materials are described by Becker at al. in U.S. PatentApplication No. 2005/0133046, Ser. No. 10/738,317, filed on Dec. 17,2003, titled Compositions and Methods for Improved Occlusion of VascularDefects and by Cohen et al. in U.S. Patent Application No. 2006/0083721,Ser. No. 11/229,119, filed on Sep. 19, 2005, titled InjectableCross-Linked Polymeric Preparations and Uses Thereof, which are herebyincorporated by reference in their entirety. Some coating embodimentsmay include extracellular matrix proteins such as ECM proteins. Oneexample of such a coating may be Finale Prohealing coating which iscommercially available from Surmodics Inc., Eden Prairie, Minn.

Defect spanning structure embodiments, including occlusive meshembodiments, as well as support structure embodiments or both mayinclude an antiplatelet agent, including but not limited to aspirin,glycoprotein IIb/IIIa receptor inhibitors (including, abciximab,eptifibatide, tirofiban, lamifiban, fradafiban, cromafiban, toxifiban,XV454, lefradafiban, kierval, lotrafiban, orbofiban, and xemilofiban),dipyridamole, apo-dipyridamole, persantine, prostacyclin, ticlopidine,clopidogrel, cromafiban, cilostazol, and nitric oxide. To deliver nitricoxide, the device embodiments may include a polymer that releases nitricoxide such as described by West et al., in U.S. Patent Application2003/0012816, based on PCT filing dated Sep. 4, 2001, titled NitricOxide-Producing Hydrogel Materials, which is incorporated by referenceherein in its entirety. Device embodiments may also deliver or includean anticoagulant such as heparin, low molecular weight heparin, hirudin,warfarin, bivalirudin, hirudin, argatroban, forskolin, ximelagatran,vapiprost, prostacyclin and prostacyclin analogues, dextran, syntheticantithrombin, Vasoflux, argatroban, efegatran, tick anticoagulantpeptide, Ppack, HMG-CoA reductase inhibitors, and thromboxane A2receptor inhibitors.

Bioactive agents suitable for use in the embodiments discussed hereinmay include those having a specific action within the body as well asthose having nonspecific actions. Specific action agents are typicallyproteinaceous, including thrombogenic types and/or forms of collagen,thrombin and fibrogen (each of which may provide an optimal combinationof activity and cost), as well as elastin and von Willebrand factor(which may tend to be less active and/or expensive agents), and activeportions and domains of each of these agents. Thrombogenic proteinstypically act by means of a specific interaction with either plateletsor enzymes that participate in a cascade of events leading eventually toclot formation. Agents having nonspecific thrombogenic action aregenerally positively charged molecules, e.g., polymeric molecules suchas chitosan, polylysine, poly(ethylenimine) or acrylics polymerized fromacrylimide or methacrylamide which incorporate positively-charged groupsin the form of primary, secondary, or tertiary amines or quartemarysalts, or non-polymeric agents such as (tridodecylmethylammoniumchloride). Positively charged hemostatic agents promote clot formationby a non-specific mechanism, which includes the physical adsorption ofplatelets via ionic interactions between the negative charges on thesurfaces of the platelets and the positive charges of the agentsthemselves.

In some embodiments, the defect spanning structure and/or supportstructure may be coated with a composition that may include geneticallyengineered peptides, nanoscale structured materials or precursorsthereof (e.g., self-assembling peptides). The peptides may have withalternating hydrophilic and hydrophobic monomers that allow them toself-assemble under physiological conditions. The composition maycomprise a sequence of amino acid residues. Such compositions aredescribed by Ellis-Behnke et al. in U.S. Patent Application2007/0203062, filed Apr. 25, 2006, titled Compositions and Methods forPromoting Hemostasis and Other Physiological Activities, which is hereinincorporated in its entirety by reference.

In some embodiments, the defect spanning structure may comprise a thinmetallic film material. The thin film metal may be fabricated by sputterdeposition and may be formed in multiple layers. The thin film may be anickel-titanium alloy also known as nitinol. Methods for forming thinfilm nitinol structures are described by Gupta et al. In an undatedpaper titled “Nitinol Thin Film Three-Dimensional Devices—Fabricationand Applications”, TINI Alloy Company, 1619 Neptune Drive, San Leandro,Calif., and U.S. Pat. No. 6,746,890 by Gupta et al., filed Jul. 17,2002, titled Three Dimensional Thin Film Devices and Methods ofFabrication, which are both incorporated by reference herein in theirentirety.

In some embodiments, the defect spanning structure may be formed atleast in part of a dissolvable polymer that is cast into a thin film.The film may be made by spraying the dissolved polymer onto a mandrelthat has a surface with the desired shape of the membrane. The polymermay be dissolved using various solvents including but not limited toDimethyl Acetamide (DMAC), Tetrahydrofuran (THF), Methyl Ethyl Ketone(MEK), Acetone, and Cyclohexanone. The amount of solvent in thedissolved polymer mixture may be high, that is greater than about 70% toproduce a low viscosity mixture that produces a thin layer in each coat.A mixture of two or more solvents may be used to achieve the bestmembrane formation. In some embodiments, the mixture may be between 70%and 95% THF and between 5% and 25% DMAC. The sprayer may include asolution reservoir and an atomization chamber (nozzle) where air, at thecorrect pressure atomizes the solution. The solvent in the solution isallowed to evaporate either in a forced convection environment or in anoven or a combination of both. The resulting material is a very thinlayer of polymer. Several other layers can then be sprayed on the thinpolymer layer to achieve a desired thickness. The defect spanningstructure may be formed in two spraying steps. In this case a firstmembrane may be cast and secured to a support structure. A secondmembrane may be then sprayed on the support structure side such that thesolvent may be allowed to partially dissolve the membrane and fuse themembrane and the newly sprayed polymer once the solvent is allowed toevaporate. Thus the second layer is formed with struts of a supportstructure encapsulated between the two layers of the polymer layer.

Support structure embodiments may be configured to hold defect spanningstructure embodiments in place which spans a vascular defect to allowhealing, clotting mechanisms and/or vaso-occlusive materials to occludethe defect space. Methods are discussed that enable the defect spanningstructure to be accurately positioned within a luminal organ such thatit substantially covers the defect opening (e.g., aneurysm neck) andthus substantially blocks flow into the defect without covering large orsignificant portions of the parent vessel that may inadvertently occludeother blood vessels. Optionally, some device embodiments may be used toblock the flow into a vessel that is intended to be occluded.

In any of the suitable device embodiments discussed herein, the supportstructure may include one or more fixation elements or surfaces tofacilitate fixation of the device within a blood vessel or othervascular site. The fixation elements may comprise hooks, barbs,protrusions, pores, microfeatures, texturing, bioadhesives orcombinations thereof. Embodiments of the support structure may befabricated from a tube of metal where portions are removed. The removalof material may be done by laser, electrical discharge machining (EDM),photochemical etching and traditional machining techniques. In someembodiments, the support structure may have an initial manufacturedconfiguration that is substantially tubular, as shown in FIGS. 39 and 49discussed below. In any of the described embodiments, the supportstructure may be constructed with a plurality of wires, cut or etchedfrom a sheet of a material, cut or etched from a tube or a combinationthereof as in the art of vascular stent fabrication.

Support structure embodiments may be formed at least in part of wire,ribbon, or other filamentary elements. These filamentary elements mayhave circular, elliptical, ovoid, square, rectangular, or triangularcross-sections. Support structure embodiments may also be formed usingconventional machining, laser cutting, electrical discharge machining(EDM) or photochemical machining (PCM). If made of a metal, it may beformed from either metallic tubes or sheet material. Some PCM processesfor making stents are described in U.S. Pat. No. 5,907,893 byZadno-Azizi et al., titled “Methods for the manufacture of radiallyexpansible stents”, filed Jan. 31, 1997 and in U.S. Patent Application2007/0031584 by Roth, titled “Thin film stent”, filed Oct. 10, 2006which are both incorporated by reference herein in their entirety.

Support structure embodiments may further include fixation elementsand/or one or more sealing members that extend from one or more of thesupport structure struts at or near the proximal end of the device tofacilitate fixation of the device within the vascular defect. Fixationor sealing member embodiments may extend radially from the axis of asupport structure thereby engaging the neck and/or inner surface of aparent blood vessel. A sealing member 62 having a substantially annularconfiguration may be secured to a proximal portion of a supportstructure 58 and sealed against a tissue surface of a patient's vasculardefect, such as an aneurysm neck 64, as shown in FIG. 14. The fixationmembers may include a coating or small surface features such as pores,voids, filaments, barbs, fibers, or strands that engage, penetrate orotherwise facilitate attachment to the adjacent tissue. Pores or voidsin the surface may be filled with a bioadhesive. Optionally, thefixation/sealing member(s) may be fabricated from a swellable material.Potentially suitable expansible swellable materials may include foams,sponge-like materials and hydrogels to facilitate sealing, fixationand/or healing of the device. Such materials may include microporousmaterials such as an open-celled foam, sponge, or other cellularstructure. A potentially suitable swellable hydrogel is described inU.S. Pat. No. 6,878,384 by Cruise et al., titled “Hydrogels that undergovolumetric expansion in response to changes in their environment andtheir methods of manufacture and use”, filed Mar. 13, 2001 which isincorporated by reference herein in its entirety. The expansiblematerial may be formed into a torodial ring 66 about the periphery ofthe defect spanning structure 68 as shown in FIG. 15. A supportstructure 70 embodiment may be deployed adjacent a vascular defect 72 soas to position the defect spanning structure 68 across the neck of thevascular defect 72.

Device embodiments discussed herein may be delivered and deployed from adelivery and positioning system that includes a microcatheter, such asthe type of microcatheter that is known in the art of neurovascularnavigation and therapy. Device embodiments may be elastically collapsedand restrained by a tube or other radial restraint for delivery anddeployment. The device may be delivered through a catheter such as amicrocatheter for endovascular treatment of cerebral aneurysms. Themicrocatheter may generally be inserted through a small incisionaccessing a peripheral blood vessel such as the femoral artery. Themicrocatheter may be delivered or otherwise navigated to a desiredtreatment site from a position outside the patient's body over aguidewire under fluoroscopy or by other suitable guiding methods. Theguidewire may be removed during such a procedure to allow insertion ofthe device through the catheter lumen in some methods.

Delivery and deployment of device embodiments discussed herein may becarried out by compressing the device to a radially constrained andlongitudinally flexible state. The device is then delivered to a desiredtreatment site within the catheter, and then ejected or otherwisedeployed from a distal end of the microcatheter. The device is thenallowed to assume an expanded relaxed or partially relaxed state withthe defect spanning structure of the device spanning or partiallyspanning a portion of the vascular defect or the entire vascular defect.The support structure will also be allowed to assume an expanded relaxedstate so as to engage a portion of a patient's vasculature adjacent toor within the vascular defect to be treated. The device may also beactivated by the application of an energy source to assume an expandeddeployed configuration once ejected from the distal section of themicrocatheter. Once the device is deployed at a desired treatment site,the microcatheter may then be withdrawn.

Delivery and positioning system embodiments may provide for the abilityto rotate a device for treatment of a patient's vasculature in-vivowithout translating torque along the entire length of the deliveryapparatus. Some embodiments for delivery and positioning devices aredescribed in co-owned U.S. Provisional Patent Application Ser. No.60/941,916 by Cox et al. titled “Apparatus and Methods for Positioningand Delivery of Endoluminal Medical Devices, filed Jun. 4, 2007 which isincorporated by reference herein in its entirety. Embodiments of thedelivery and positioning apparatus, discussed in more detail below withreference to FIGS. 64-72, may include a distal rotating member thatallows rotational positioning of the vascular defect support structure.The delivery and positioning apparatus may include a distal rotatingmember which rotates the implant in-vivo without the transmission oftorque along the entire length. Optionally, delivery system may alsorotate the implant without the transmission of torque in theintermediate portion between the proximal end and the distal rotatableend. The delivery and positioning apparatus may be releasably secured tothe defect spanning structure, support structure or any other suitableportion of the device for treatment of a patient's vasculature.

Device embodiments discussed herein may be releasable from a flexible,elongate delivery apparatus such as a guidewire or guidewire-likestructure. The release of device embodiments from such a deliveryapparatus may be activated by a thermal mechanism, electrolyticmechanism, hydraulic mechanism, shape memory material mechanism, or anyother mechanism known in the art of endovascular implant deployment.Potentially suitable thermal release mechanisms are described by Gandhiet al. in U.S. Patent Application 2006/0253149, filed May 16, 2006,titled Apparatus for Deployment of Micro-Coil Using a Catheter, and byFitz et al. in U.S. Patent Applications 2006/0052815, filed Aug. 25,2005, titled Thermal Detachment System for Implantable Devices, and2006/0200192, filed May 3, 2006, titled Thermal Detachment System forImplantable Devices, which are both incorporated by reference herein intheir entirety.

Embodiments for deployment and release of therapeutic devices, such asdeployment of embolic devices or stents within the vasculature of apatient, may include connecting such a device via a releasableconnection to a distal portion of a pusher or acutator member. Thetherapeutic device may be detachably mounted to the distal portion ofthe pusher member by a filamentary tether, string, thread, wire, fiber,or the like, which may be referred to as the tether. The tether may bein the form of a monofilament, rod, ribbon, hollow tube, or the like.Some embodiments of the tether may have a diameter or maximum thicknessof between about 0.05 mm and 0.2 mm. The tether may be configured to beable to withstand a maximum tensile load of between about 0.5 kg and 5kg. The tether may be severed by the Input of energy such as electriccurrent to a heating element causing release of the therapeutic device.For some embodiments, the heating element may be a coil of wire withhigh electrical resistivity such as a platinum-tungsten alloy. Thetether member may pass through or be positioned adjacent the heaterelement. The heater may be contained substantially within the distalportion of the pusher member to provide thermal insulation to reduce thepotential for thermal damage to the surrounding tissues duringdetachment. In another embodiment, current may pass through the tetherwhich also acts as a heating element.

Many materials may be used to make tether embodiments includingpolymers, metals and composites thereof. One class of materials that maybe useful for tethers includes polymers such as polyolefin, polyolefinelastomer such as polyethylene, polyester (PET), polyamide (Nylon),polyurethane, polypropylene, block copolymer such as PEBAX or Hytrel,and ethylene vinyl alcohol (EVA); or rubbery materials such as silicone,latex, and Kraton. In some cases, the polymer may also be cross-linkedwith radiation to manipulate its tensile strength and melt temperature.Another class of materials that may be used for tether embodiment mayinclude metals such as nickel titanium alloy (Nitinol), gold, platinum,tantalum and steel. Other materials that may be useful for tetherconstruction includes wholly aromatic polyester polymers which areliquid crystal polyers (LCP) that may provide high performanceproperties and are highly inert. A commercially available LCP polymer isVectran, which is produced by Kuraray Co. (Tokyo, Japan). The selectionof the material may depend on the melting or softening temperature, thepower used for detachment, and the body treatment site. The tether maybe joined to the implant and/or the pusher by crimping, welding, knottying, soldering, adhesive bonding, or other means known in the art.

Embodiments of devices and methods for release and deployment of atherapeutic device within the vasculature of a patient may include anelongate, flexible pusher member having an interior lumen, and a distalportion. The distal portion may include a mechanism for detachablymounting the therapeutic device to the pusher member. In general, suchdeployment apparatus embodiments may be inserted into a patient using acatheter or other tubular access device. The therapeutic device may bepositioned at a desired placement or treatment site within a patient'svasculature and energy may then be delivered to a heating element whichheats a tether causing it to fail by breaking, melting or any othersuitable mechanism. Failure of the tether results in detachment of thetherapeutic device from the pusher member and deployment of thetherapeutic device in the patient's vasculature at the desired site.

Any embodiment of devices for treatment of a patients vasculature,delivery system for such devices or both discussed herein may be adaptedto deliver energy to the device for treatment of a patient's vasculatureor to tissue surrounding the device at the implant site for the purposeof facilitating fixation of a device, healing of tissue adjacent thedevice or both. In some embodiments, energy may be delivered through adelivery system to the device for treatment of a patient's vasculaturesuch that the device is heated. In some embodiments, energy may bedelivered via a separate elongate instrument (e.g., catheter) to thedevice for treatment of a patient's vasculature and/or surroundingtissue at the site of the implant. Examples of energy embodiments thatmay be delivered include but are not limited to light energy, thermal orvibration energy, electromagnetic energy, radio frequency energy andultrasonic energy. For some embodiments, energy delivered to the devicemay trigger the release of chemical or biologic agents to promotefixation of a device for treatment of a patient's vasculature to apatient's tissue, healing of tissue disposed adjacent such a device orboth.

Defect spanning structure embodiments may be configured to react to thedelivery of energy to effect a change in the mechanical or structuralcharacteristics, deliver drugs or other bioactive agents or transferheat to the surrounding tissue. For example, either the supportstructure and/or the defect spanning structure of device embodiments maybe made softer or more rigid from the use of materials that changeproperties when exposed to electromagnetic energy (e.g., heat, light, orradio frequency energy). Application of an agent in combination withenergy to a region of blood vessel wall weakness to strengthen the walland/or inducing fibrosis is discussed in U.S. Pat. No. 6,719,7789, toVan Tassel, et al. filed Mar. 24, 2000, titled “Methods for Treatment ofAneurysms”, which is incorporated by reference herein in its entirety.In another example, the defect spanning structure may include a polymerthat reacts in response to physiologic fluids by expanding. An exemplarymaterial is described by Cox in U.S. Patent Application No.2004/0186562, filed Jan. 22, 2004, titled “Aneurysm Treatment Device andMethod of Use”, which is incorporated by reference herein in itsentirety.

Referring to FIG. 16, an embodiment of a device for treatment of apatient's vasculature 100 is shown in an expanded deployed state. Asupport structure 102 of the device includes strut members disposed in asubstantially tubular configuration. The support structure is configuredto span or cross the lumen of a parent vessel 104 both upstream anddownstream of the vascular defect shown in the form of a berry aneurysm108 extending from the parent vessel 104. A defect spanning structure108 of the device is configured to substantially block flow of bloodinto the vascular defect when positioned substantially over the defectas shown. The expandable body support structure 102 includes a lowprofile radially constrained state as shown in FIG. 17 where the device100 is disposed within a distal portion of a catheter 110.

The support structure 102 further includes a first end, a second end andan elongated tubular configuration having a longitudinal axis. Theelongate flexible struts are connected or otherwise secured atintersections between the first end and second end forming a pluralityof open cells between struts in a middle portion of the expandable body.The elongated tubular configuration has a first transverse dimension ina radially compressed state that is suitable for delivery from amicrocatheter configured for navigation in a patient's cerebralvasculature as shown in FIG. 17. The radial constraint on the device maybe applied by an inside surface of the inner lumen of the microcatheter110, or it may be applied by any other suitable mechanism or structurethat may be released or withdrawn in a controllable manner so as toeject the device from the distal end of the catheter.

The tubular configuration has an expanded relaxed state with a tubularconfiguration having a second transverse dimension substantially greaterthan the first transverse dimension of the tubular configuration of theconstrained state which is configured to engage tissue of a patient'svasculature adjacent a vascular defect 106 as shown in FIG. 16. Theengagement of the tubular member of the support structure 102 may beachieved by the exertion of an outward radial force against tissue ofthe patient's vessel of the tubular support structure. Such a force maybe exerted in some embodiments wherein the nominal outer transversedimension or diameter of the support structure in the relaxedunconstrained state is larger than the nominal inner transversedimension of the vessel within which the support structure is beingdeployed. The elastic resiliency of the support structure may beachieved by an appropriate selection of materials, such as superelasticalloys, including nickel titanium alloys, stainless steel, or any othersuitable material.

The defect spanning structure 108 in the form of a permeable layer spansat least one cell between struts of the expandable body and may bedisposed against the opening to the vascular defect 106 so as to closeoff the opening to the vascular defect as shown in FIG. 16. The defectspanning structure may include any of the materials discussed aboveincluding perforated membranes, laser cut polymer membranes,microfibers, including electrospun microfibers, as well as others. Thedefect spanning structure may be secured to the support structure byadhesive bonding, suturing, lacing, or any other suitable method.

For some embodiments, the struts of the expandable body 102 may includeperforations or holes which are configured for securing the permeablelayer to the expandable body by lacing, suturing or the like. The defectspanning structure 108 in the form of a permeable layer may be disposedinterior to an outer surface of the expandable body. The defect spanningstructure may also include multiple layers. For some multiple layerembodiments, an outer layer may include an anti-thrombogenic agent andan inner layer disposed towards a cavity of a the vascular defect, suchas the aneurysm shown, may include a thrombogenic agent that may beeluted therefrom, and particularly, eluted into the vascular defect. Forsome embodiments, the inner layer and outer layer may be securedtogether in a monolithic structure. For some embodiments, the permeablelayer may include a thin membrane having a combination of macropores andmicropores. For some embodiments, the macropores may have a transversedimension of about 100 microns to about 500 microns and the microporeshave a transverse dimension of about 10 microns to about 100 microns.

Some embodiments may include a sealing member (not shown) disposed abouta perimeter of the permeable layer and configured to form a seal betweenthe permeable layer and a surface of the patient's vasculature. Someembodiments of the sealing member may include a swellable polymer. Forsome embodiments, a total volume of the permeable layer may be less thanabout 5 mm3. For some embodiments, a total volume of permeable layer maybe between about 0.5 mm3 and 4 mm3. For some embodiments, the permeablelayer may have a porosity greater than about 60 percent and a thicknessof less than about 50 microns. For some embodiments, the permeable layermay be about 2 microns to about 10 microns thick. For some embodiments,the expandable body of the support structure may have a first transversedimension in a collapsed state configured for intraluminal delivery ofabout 0.2 mm to about 2 mm and a second transverse dimension in anexpanded relaxed state after deployment or delivery of about 4 mm toabout 30 mm.

A delivery system, such as any suitable embodiment of the deliverysystems discussed and incorporated herein, may be used that allows foraccurate positioning such that the defect spanning structure 108substantially covers the defect opening or neck as shown in FIG. 16. Thedevice 100 may be implanted substantially in a blood vessel 104 with thedefect or “parent vessel”. However, in some embodiments, a portion ofthe device 100 may extend into the defect opening or neck or into branchvessels. In some embodiments, the support structure comprises strutmembers that cross or span the lumen of the parent vessel both upstreamand/or downstream of the vascular defect 106. Axial movement anddeployment of the device 100 from a delivery system that includes amicrocatheter 110 may be controlled by an elongate actuator member 112that extends from a proximal end of the microcatheter 110 to a distalend thereof. The actuator 112 may also include a release mechanism 114disposed on a distal end thereof that releasably secures a distal end ofthe actuator member 112 to the device. The release mechanism 114 mayinclude any suitable embodiment of release or detachment mechanismsdiscussed herein.

FIG. 18 illustrates an embodiment of a device for treatment of apatient's vasculature 130 that has a similar configuration to that ofthe device 100 illustrated in FIGS. 16 and 17. The device for treatmentof a patient's vasculature 130 is shown in an expanded deployed state inFIG. 18 with the support structure 132 of the device 130 engaged withthe patient's vascular tissue of the vessel 104 adjacent the vasculardefect 106. The support structure 132 of the device includes strutmembers configured to span or cross the lumen of a parent vessel bothupstream and downstream of the vascular defect 106 shown in the form ofa berry aneurysm extending from the parent vessel 104. The struts of thesupport structure may include undulated portions that are configured toelastically absorb axial compression and extension. A defect spanningstructure 134 of the device is configured to substantially block flow ofblood into the vascular defect 106 when positioned substantially overthe defect as shown. The expandable body support structure 132 includesa low profile radially constrained state as shown in FIG. 19 that issuitable for delivery to a target vascular defect within a patient'sbody from a delivery system, such as the delivery system embodimentsdiscussed herein. Some such delivery system embodiments may include oneor more microcatheters 110, guidewires as well as other devices.

The support structure 132 further includes a first end, a second end andan elongated tubular configuration having a longitudinal axis. Theelongate flexible struts are connected or otherwise secured atintersections between the first end and second end forming a pluralityof open cells between struts in a middle portion of the expandable body.The elongated tubular configuration has a first transverse dimension ina radially compressed state that is suitable for delivery from amicrocatheter 110 configured for navigation in a patient's cerebralvasculature as shown in FIG. 19.

The tubular configuration has an expanded relaxed state with a tubularconfiguration having a second transverse dimension substantially greaterthan the first transverse dimension of the tubular configuration of theconstrained state which is configured to engage tissue of a patient'svasculature adjacent a vascular defect 106 as shown in FIG. 18. Theelastic resiliency of the support structure 132 may be achieved by anappropriate selection of materials, such as superelastic alloys,including nickel titanium alloys, stainless steel, or any other suitablematerial. The defect spanning structure 134 of the device is integrallyformed from the same material as the support structure 132 and includesa high density porous region that is configured to be disposed againstthe opening to the vascular defect 106 so as to close off the opening tothe vascular defect as shown in FIG. 18. The defect spanning structure134 may be coated with a variety of materials including any of thecoating, bioactive or polymer materials discussed above.

Some embodiments may include a sealing member (not shown) disposed abouta perimeter of the defect spanning structure and configured to form aseal between the permeable layer and a surface of the patient'svasculature. Some embodiments of the sealing member may include aswellable polymer. For some embodiments, the permeable layer may have aporosity greater than about 60 percent. For some embodiments, thesupport structure 132 may have a first transverse dimension in acollapsed state of about 0.2 mm to about 2 mm and a second transversedimension of about 4 mm to about 30 mm.

FIG. 20 illustrates a device for treatment of a patient's vasculature200 that includes a support structure 202 and a defect spanningstructure 204. The support structure 202 includes an expandable bodywith a first end 206 and a second end 208. The defect spanning structure204 is disposed at the second end of the expandable body and may includea permeable layer which conforms to a profile of the second end 208 ofthe expandable body in a relaxed expanded state. When in a relaxed,expanded state, as when deployed in a vascular defect such as terminalaneurysm 210, the first end portion of the expandable body has a tubularconfiguration, which may be engaged with a parent vessel 212, and thesecond end portion has a somewhat bulbous or spherical configuration.Second ends of the struts of the expandable body may be secured togetherrelative to each other. The expandable body also has a low profileradially constrained state, as shown in FIG. 21, with an elongatedtubular configuration that includes a longitudinal axis with theelongate flexible struts of the second end portion disposedsubstantially parallel to each other. The radial constraint on thedevice 200 may be applied by an inside surface of the inner lumen of themicrocatheter 110, or it may be applied by any other suitable mechanismthat may be released in a controllable manner upon ejection of thedevice from the distal end of the catheter. For example, a severableband or fiber may constrain the device until severed by the applicationof energy (e.g., heat) or mechanical means.

The bulbous second end portion of the expandable body has a firsttransverse dimension with a low profile suitable for delivery from amicrocatheter 110 and an expanded relaxed state having an axiallyshortened configuration relative to the constrained state with eachstrut forming a smooth arc such that the are of each strut extendsaxially beyond the first transverse dimension. In the expanded state thesecond end portion has a second transverse dimension substantiallygreater than the first transverse dimension. One or more of the strutsmay be configured to independently flex in a radial orientation withrespect to the longitudinal axis of the expandable body.

The tubular configuration of the first end 206 of the expandable bodymay include a trunk portion with an open upstream end that extends intoand engages one of the patient's vessels, which may include the parentvessel 212. For some embodiments, the trunk portion may be deployed toextend into the parent vessel of a terminal bifurcation such that thebulbous second end portion of the device is positioned at an apexportion of the bifurcation as shown in FIG. 20. Such embodiments may beuseful for the treatment of basilar tip aneurysm embodiments. Theengagement of the tubular portion of the first end portion 206 of thesupport structure 202 may be achieved by the exertion of an outwardradial force against tissue of the patient's vessel 212 of the tubularsupport structure. Such a force may be exerted in some embodimentswherein the nominal outer transverse dimension or diameter of thesupport structure in the relaxed unconstrained state is larger than thenominal inner transverse dimension of the vessel within which thesupport structure is being deployed. The elastic resiliency of thesupport structure 202 may be achieved by an appropriate selection ofmaterials, such as superelastic alloys, including nickel titaniumalloys, stainless steel, or any other suitable material.

Embodiments of the permeable layer of the defect spanning structure 204may include a convex configuration that spans the second end of theexpandable body in a relaxed expanded state and extends along the strutstowards the first end. In some embodiments, the permeable layer may spanthe struts of the support structure towards the first end to alongitudinal position of about 10 percent to about 60 percent the totallength of the expandable body when the expandable body is in a relaxedexpanded state. The defect spanning structure 204 may include any of thematerials discussed above including perforated membranes, laser cutpolymer membranes, microfibers, including electrospun microfibers, aswell as others. The defect spanning structure may be secured to thesupport structure by adhesive bonding, suturing, lacing, or any othersuitable method.

For some embodiments, the struts of the expandable body 202 may includeperforations which are configured for securing the permeable layer tothe expandable body by lacing, suturing or the like. The defect spanningstructure 204 in the form of a permeable layer may be disposed interiorto an outer surface of the expandable body. The defect spanningstructure may also include multiple layers. For some multiple layerembodiment, an outer layer may include an anti-thrombogenic agent and aninner layer disposed towards a cavity of a the vascular defect, such asthe aneurysm shown, may include a thrombogenic agent that may be elutedtherefrom, and particularly, eluted into the vascular defect to promotethrombosis, stabilization or healing of the vascular defect. For someembodiments, the inner layer and outer layer may be secured together ina monolithic structure. For some embodiments, the permeable layer mayinclude a thin membrane having a combination of macropores andmicropores. For some embodiments, the macropores may have a transversedimension of about 100 microns to about 500 microns and the microporeshave a transverse dimension of about 10 microns to about 100 microns.

For some embodiments, a total volume of the permeable layer may be lessthan about 5 mm3. For some embodiments, a total volume of permeablelayer may be between about 0.5 mm3 and 4 mm3. For some embodiments, thepermeable layer may have a porosity greater than about 60 percent and athickness of less than about 50 microns. For some embodiments, thepermeable layer may be about 2 microns to about 10 microns thick. Forsome embodiments, the expandable body of the support structure may havea first transverse dimension in a collapsed state of about 0.2 mm toabout 2 mm and a second transverse dimension in a relaxed deployed stateof about 4 mm to about 30 mm. Some embodiments of the device 200 mayinclude a sealing member (not shown) disposed about a perimeter or othersuitable portion of the permeable layer, or defect spanning structure204 generally, and be configured to form a seal between the permeablelayer and a surface of the patient's vasculature. Some embodiments ofthe sealing member may include a swellable polymer.

A delivery system, such as the delivery systems discussed above, may beused that allows for accurate positioning such that the defect spanningstructure 204 substantially covers the defect opening or neck of thevascular defect as shown in FIG. 20. The device 200 may be implantedsubstantially in a blood vessel with the defect or parent vessel 212.However, in some embodiments, a portion of the device may extend intothe defect opening or neck or into branch vessels. In some embodiments,the support structure 202 includes strut members that cross or span thelumen of the parent vessel both upstream and/or downstream of thevascular defect. Axial movement and deployment of the device from themicrocatheter 110 may be controlled by an actuator member 112 andrelease mechanism 114 that releasably secures the actuator member to thedevice 200 as shown in FIG. 21. The release mechanism may include anysuitable embodiment of release mechanisms discussed above.

FIGS. 22 and 23 show embodiments of devices for treatment of a patient'svasculature that have configurations that are similar in some respectsto the device of FIGS. 20 and 21. However, the embodiments of FIGS. 22and 23 include a generally tubular support structure, a defect spanningstructure that has at least some surface substantially perpendicular toan axis of the support structure and a connecting structure whichconnects the support structure to the defect spanning structure as shownin FIG. 22. The connecting structure and defect spanning structure mayinclude one or more flexible elements to facilitate conformance of thedefect spanning structure to anatomical variations of the patient'svasculature adjacent the vascular defect to be treated as shown in FIG.23. Variations in the patient's vasculature may include angulardeviations, dimensional deviations, off axis vascular defects and thelike.

FIG. 22 illustrates an embodiment of a device for treatment of apatient's vasculature 220 including a support structure 222 and a defectspanning structure 224. The support structure 222 includes an expandablebody with a first end 226 and a second end 228. The defect spanningstructure 224 is disposed at the second end 228 of the expandable bodyand may include a permeable layer which conforms to a profile of asecond end platform of the expandable body in a relaxed expanded state.When in a relaxed, expanded state, the first end portion of theexpandable body has a tubular configuration. The second end platform iscoupled to the tubular first end portion by a connecting structure 230in the form of strut members. The expandable body has a low profileradially constrained state (not shown) with an elongated configuration.When the device 220 is in a collapsed, radially constrained state, asdiscussed above with regard to other embodiments and shown in FIG. 22A,the radial constraint on the device 220 may be applied by an insidesurface of an inner lumen of a microcatheter 110, or it may be appliedby any other suitable mechanism that may be released in a controllablemanner upon ejection of the device from the distal end of the catheter110.

Referring to FIG. 23, the device for treatment of a patient'svasculature 240 is shown that includes a support structure 242 and adefect spanning structure 244. The support structure 242 includes anexpandable body with a first end 246 and a second end 248. The defectspanning structure 244 is disposed at the second end 248 of theexpandable body and may include a permeable layer which conforms to aprofile of a second end platform of the expandable body when the deviceis in a relaxed expanded state. When in a relaxed, expanded state, thefirst end portion of the expandable body may have a substantiallytubular configuration.

The second end platform is coupled to the tubular first end portion by aconnecting structure 250 in the form of a flexible coupling that extendsgenerally along the longitudinal axis of the expandable body member. Theflexible coupling may include one or more flexing members 252. Thesecond end platform of the expandable body may be nominally disposedsubstantially perpendicular to the longitudinal axis of the tubularfirst end portion of the expandable body in a relaxed state but isconfigured to flex or otherwise deflect at the flexible coupling in anyangular orientation or direction perpendicular to the longitudinal axisin order to accommodate a patient's anatomical variations. For someembodiments, the second end platform of the defect spanning structuremay flex over an angle of up to about 40 degrees from perpendicular withthe longitudinal axis of the first end tubular portion, morespecifically, up to about 20 degrees from perpendicular with thelongitudinal axis of the first end tubular portion of the device.

The engagement of the tubular portion of the first end portion of thesupport structure 242 may be achieved by the exertion of an outwardradial force against tissue of the patient's vessel 212 of the tubularsupport structure. Such a force may be exerted in some embodimentswherein the nominal outer transverse dimension or diameter of the firstend tubular portion of the support structure 242 in the relaxedunconstrained state is larger than the nominal inner transversedimension of the vessel within which the support structure is beingdeployed. The elastic resiliency of the support structure may beachieved by an appropriate selection of materials, such as superelasticalloys, including nickel titanium alloys, stainless steel, or any othersuitable material.

Embodiments of the defect spanning structure 244 and permeable layerthereof may include a convex configuration that spans the second endplatform portion of the expandable body. The second end platform portionmay include one or more strut or frame members that may be made from thesame or a similar material as the material of the first end tubularportion of the device. The struts or frame members of the second endplatform as well as the flexible coupling member 250 may also be acontinuous or monolithic structure with respect to the first end tubularportion and support structure 242 generally. In some embodiments, thepermeable layer and defect spanning structure 244 may have a majortransverse dimension across the outer surface of the platform of about 4mm to about 30 mm. The defect spanning structure 244 may include any ofthe materials discussed above including perforated membranes, laser cutpolymer membranes, microfibers, including electrospun microfibers, aswell as others. The defect spanning structure 244 may be secured to thestrut or frame members of the second end platform by adhesive bonding,suturing, lacing, or any other suitable method.

For some embodiments, the struts of the second end platform portion mayinclude perforations which are configured for securing the permeablelayer to the expandable body by lacing, suturing or the like. Thepermeable layer of the defect spanning structure 244 may be disposed oneither side of the frame or strut members of the second end platform.The defect spanning structure 244 may also include multiple layers. Forsome multiple layer embodiments, an outer layer which is exposed to apatient's vasculature system includes an anti-thrombogenic agent. Aninner layer disposed towards a cavity of a vascular defect, such as theaneurysm shown, may include a thrombogenic agent that may be elutedtherefrom, and particularly, eluted into the vascular defect. For someembodiments, the inner layer and outer layer may be secured together ina monolithic structure. For some embodiments, the permeable layer mayinclude a thin membrane having a combination of macropores andmicropores. For some embodiments, the macropores may have a transversedimension of about 100 microns to about 500 microns and the microporeshave a transverse dimension of about 10 microns to about 100 microns.

For some embodiments, a total volume of the permeable layer may be lessthan about 5 mm3. For some embodiments, a total volume of permeablelayer may be between about 0.5 mm3 and 4 mm3. For some embodiments, thepermeable layer may have a porosity greater than about 60 percent and athickness of less than about 50 microns. For some embodiments, thepermeable layer may be about 2 microns to about 10 microns thick. Forsome embodiments, the expandable body of the support structure may havea first transverse dimension in a collapsed state of about 0.2 mm toabout 2 mm and a second transverse dimension in a relaxed state of about4 mm to about 30 mm. Some embodiments of the device 240 may include asealing member (not shown) disposed about a perimeter or other suitableportion of the permeable layer, or defect spanning structure 244generally, and be configured to form a seal between the permeable layerand a surface of the patient's vasculature. Some embodiments of thesealing member may include a swellable polymer.

Delivery systems and methods, such as any of the delivery systems andmethods discussed herein, may be used to deliver either of the deviceembodiments shown in FIGS. 22 and 23. The devices of FIGS. 22 and 23 maybe delivered by microcatheter embodiments 110 when disposed in acollapsed radially constrained state as shown in FIGS. 22A and 24,respectively. Such delivery devices and methods allow for accuratepositioning such that the defect spanning structure substantially coversthe defect opening or neck as shown in FIGS. 22 and 23. The device maybe implanted substantially in a blood vessel with the defect 210 orparent vessel 212. However, in some embodiments, a portion of the devicemay extend into the defect opening or neck or into branch vessels.

Referring to FIG. 25, a device for treatment of a patient's vasculature300 is shown that includes a support structure 302 that includes anexpandable body with a first end 304 and a second end 306. A defectspanning structure 308 is disposed at the second end 306 of theexpandable body and may include a permeable layer which conforms to aprofile of the second end of the expandable body when the expandablebody is in a relaxed expanded state. When in a relaxed, expanded state,the expandable body may have a substantially spherical or globular shapewith a first end portion of the expandable body 302 having asubstantially hemispherical configuration and a second end portion alsohas a somewhat bulbous or hemispherical configuration. First ends andsecond ends of the struts of the expandable body may be secured togetherrelative to each other and allow the ends to pivot relative to eachother so as to allow expansion of the expandable body.

The expandable body also has a low profile radially constrained state,as shown in FIG. 26, with an elongated configuration that includes alongitudinal axis. In the collapsed, radially constrained state, theelongate flexible struts of the expandable body may be disposedsubstantially parallel to each other. The radial constraint on thedevice may be applied by an inside surface of the inner lumen of amicrocatheter 110, such as the distal end portion of the microcathetershown in FIG. 26, or it may be applied by any other suitable mechanismthat may be released in a controllable manner upon ejection of thedevice from the distal end of the catheter 110 to allow outwardself-expansion of the expandable body and device 300.

Embodiments of the support structure 302 form a spherical, bulbous orglobular structure. The defect spanning structure 308 may have lowporosity, small pores or no porosity at all and a second portion that isfenestrated or open-celled and highly porous to blood flow. Thestructure 302 may include strut members made of wire or cut from sheetor tube stock. While the device 300 may have a substantially spherical,bulbous or globular shape in its natural, relaxed, undeformed or minimumenergy state, the structure may be compliant to conform to variousvessel anatomy; thus, the shape after implantation may have deviationsfrom its natural shape. The portion of device 300 surface area that isof lower or no porosity may be less than about 25% of the total surfacearea. The support structure 302 may be substantially hollow. The devicemay be deployed such that the defect spanning portion 308 is positionedsubstantially covering the opening or neck of a vascular defect 210 asshown in FIG. 25. The device may be particularly useful in the treatmentof bifurcation aneurysms or terminal aneurysms 210 that lie at thejunction or terminus where a vessel 212 is branching into two vessels.When the device is used to treat a terminal aneurysm 210, the devicestructure may be placed at the junction of the three vessels making upthe bifurcation and at least one strut member crosses or spans the lumenof all three vessels. For some embodiments, the support structure 302may define a substantially closed structure with at least one diameterthat is greater than the largest vessel of those proximate an aneurysm210.

The bulbous or hemispherical second end portion of the expandable bodyhas a first transverse dimension with a low profile suitable fordelivery from a microcatheter 110. The expandable body has a secondtransverse dimension or diameter when in an expanded relaxed statehaving an axially shortened configuration relative to the constrainedstate with each strut forming a smooth arc such that the arc of eachstrut extends axially beyond the first transverse dimension. In theexpanded state the second end portion has a second transverse dimensionsubstantially greater than the first transverse dimension. One or moreof the struts may be configured to independently flex in a radialorientation with respect to the longitudinal axis of the expandablebody. The hemispherical configuration of the first end 304 of theexpandable body 302 may extend into and engage one of the patient'svessels, which may include the parent vessel 212. The bulbous second endportion of the device is positioned at an apex portion of thebifurcation as shown in FIG. 25 with the defect spanning structure 308engaged with and isolating the vascular defect 210 in the form of theterminal aneurysm shown. Such embodiments may be useful for thetreatment of basilar tip aneurysm embodiments.

The engagement of the bulbous portion of the first end portion of thesupport structure 302 may be achieved by the exertion of an outwardradial force against tissue of the patient's vessel of the supportstructure. Such a force may be exerted in some embodiments wherein thenominal outer transverse dimension or diameter of the support structure302 in the relaxed unconstrained state is larger than the nominal innertransverse dimension of the vessel within which the support structure isbeing deployed. The elastic resiliency of the support structure may beachieved by an appropriate selection of materials, such as superelasticalloys, including nickel titanium alloys, stainless steel, or any othersuitable material.

Embodiments of a permeable layer of the defect spanning structure 308may include a convex configuration that spans the second end of theexpandable body in a relaxed expanded state and extends along the strutstowards the first end. In some embodiments, the permeable layer may spanthe struts towards the first end to a longitudinal position of about 10percent to about 60 percent the total length of the expandable body whenthe expandable body is in a relaxed expanded state. The defect spanningstructure 308 may include any of the materials discussed above includingperforated membranes, laser cut polymer membranes, microfibers,including electrospun microfibers, as well as others. The defectspanning structure may be secured to the support structure by adhesivebonding, suturing, lacing, or any other suitable method.

For some embodiments of the device 300, the struts of the expandablebody of the support structure 302 may include perforations which areconfigured for securing the permeable layer to the expandable body bylacing, suturing or the like. The defect spanning structure 308 mayinclude a permeable layer which may be disposed interiorly or exteriorlyto an outer surface or structure of the expandable body. The defectspanning structure 308 may also include multiple layers. For some suchmultiple layer embodiments, an outer layer of the permeable layer mayinclude an anti-thrombogenic agent and an inner layer disposed towardsthe vascular defect 210, such as the aneurysm shown, may include athrombogenic agent that may be eluted therefrom. The thrombogenic agenteluted from the inner layer, and particularly, eluted into the vasculardefect, may promote thrombosis, stabilization or healing of the vasculardefect. For some embodiments, the inner layer and outer layer may besecured together in a monolithic structure. For some embodiments, thepermeable layer may include a thin membrane having a combination ofmacropores and micropores. For some embodiments, the macropores may havea transverse dimension of about 100 microns to about 500 microns and themicropores have a transverse dimension of about 10 microns to about 100microns.

For some embodiments, a total volume of the permeable layer of thedefect spanning structure 308 may be less than about 5 mm3. For someembodiments, a total volume of permeable layer may be between about 0.5mm3 and 4 mm3. For some embodiments, the permeable layer may have aporosity greater than about 60 percent and a thickness of less thanabout 50 microns. For some embodiments, the permeable layer may be about2 microns to about 10 microns thick. For some embodiments, theexpandable body of the support structure 302 may have a first transversedimension in a collapsed radially constrained state of about 0.2 mm toabout 2 mm and a second transverse dimension in a relaxed expanded stateof about 4 mm to about 30 mm. Some embodiments of the device 300 mayinclude a sealing member (not shown) disposed about a perimeter or othersuitable portion of the permeable layer, or defect spanning structure308 generally, and be configured to form a seal between the permeablelayer and a surface of the patient's vasculature. Some embodiments ofthe sealing member may include a swellable polymer.

A delivery system, such as the delivery systems discussed above, may beused that allows for accurate positioning such that the defect spanningstructure substantially covers the defect opening or neck as shown inFIG. 25. The device may be implanted or deployed substantially in ablood vessel 212 adjacent the defect 210. However, in some embodiments,a portion of the device 300 may extend into the defect opening or neckor into branch vessels. Axial movement and deployment of the device 300from the microcatheter 110 may be controlled by an actuator member 112and release mechanism 114 that releasably secures the actuator member tothe device as shown in FIG. 26. The delivery systems, methods andrelease mechanisms suitable for use with the device of FIG. 25 mayinclude any suitable embodiment or embodiments discussed or incorporatedherein.

In use, the device 300 shown in FIG. 25, or any other suitable deviceembodiment discussed herein, may be deployed by advancing a deliverysystem, such as the delivery system discussed above, or any othersuitable delivery system discussed or incorporated herein, to a positionadjacent a vascular defect 210 to be treated. The device 300 may then bepositioned adjacent the vascular defect 210 such as the aneurysm shownand deployed such that the expandable body self-expands adjacent thevascular defect and the defect spanning structure 308 covers at least aportion of the defect opening or neck. For some embodiments, the device300 is positioned adjacent the vascular defect 210 from a proximal endof the delivery system with an elongate actuator 112 which may bereleasably secured to the device and further comprising releasing ordetaching the device from the elongate actuator. The device 300 may bereleased or detached from the delivery system by any suitable detachmentmechanism or mechanisms. For example, thermal, mechanical, electrolytic,shape memory as well as any other suitable mechanism or mechanisms maybe used.

During deployment, the device 300 may be rotated in order to achieve adesired position prior to or during deployment of the device. For someembodiments, the device may be rotated about a longitudinal axis of thedelivery system with or without the transmission or manifestation oftorque being exhibited along a middle portion of a delivery catheter 110being used for the delivery. Suitable catheters for such use have beendescribed and incorporated herein. These delivery and deployment methodsmay be used for deployment within berry aneurysms, terminal aneurysms,or any other suitable vascular defect embodiments. Some methodembodiments include deploying the device at a confluence of threevessels of the patient's vasculature that form a bifurcation such thatthe defect spanning structure substantially covers the neck of aterminal aneurysm and one or more struts of the support structure spanor cross each of the three vessels.

For some embodiments, once the device 300 has been deployed, theattachment of platelets to the defect spanning structure may beinhibited and the formation of clot within an interior space of thevascular defect promoted or otherwise facilitated with a suitable choiceof thrombogenic coatings, anti-thrombogenic coatings or any othersuitable coatings applied either to the defect spanning structure orsupport structure adjacent thereto. Energy forms may also be appliedthrough the delivery apparatus and/or a separate catheter to facilitatefixation and/or healing of the device adjacent the vascular defect forsome embodiments. One or more embolic devices or embolic material mayalso optionally be delivered into the vascular defect adjacent thedefect spanning structure after the device has been deployed.

FIG. 27 illustrates an embodiment of a device for treatment of apatient's vasculature 320 that may have the same or similar features,dimensions and materials as those of the device of FIG. 25. The device320 of FIG. 27 is shown with at least a portion of the defect spanningstructure 322 forming a convex surface 324 that generally approximatesthe natural healthy vessel anatomy and with the first end of the defectspanning structure engaging the patient's anatomy so as to push thedefect spanning portion 322 of the device against the opening of thepatients vascular defect 210 so as to isolate the defect the interior ofthe patient's vasculature. The support structure 326 may have aconfiguration that conforms to the vasculature adjacent the vasculardefect 210.

FIG. 28 illustrates an embodiment of a device for treatment of apatient's vasculature 340 that may have the same or similar features,dimensions and materials as those of the device of FIG. 25. Theembodiment shown forms a bulbous or globular device being used in thetreatment of the side-wall aneurysms and may also be used to treataneurysms occurring at or near bifurcations but not “terminal”. Thedevice 340 in FIG. 28 is shown engaged with and isolating a typicalberry type aneurysm 106 with the defect spanning structure 342 of thedevice spanning and isolating the vascular defect 106. In someembodiments, the device 340 may include a support structure 344 havingan ovoid or elliptical cross-section and a defect spanning portion 342that lies along a side wall as shown in FIG. 28.

Referring to FIGS. 29-32, an embodiment of an intrasaccular device fortreatment of a patient's vasculature 400 is shown that is configured tobe deployed within an interior cavity of a patient's vascular defect.The device may have the same or similar features, dimensions andmaterials as those of the devices shown in FIGS. 25, 27 and 28 anddiscussed above. The device 400 may be used to treat either a side-wallor berry aneurysm 106 as shown in FIG. 31 or a bifurcation aneurysm,such as the terminal aneurysm 210 shown in FIG. 32. The device 400 maybe disposed substantially within the vascular defect when deployed andimplanted, however, in some embodiments, a portion of the device mayextend into the neck or parent vessel.

Referring to FIG. 29, the device for treatment of a patient'svasculature 400 is shown that includes a support structure 402 with anexpandable body with a first end 404 and a second end 406. A defectspanning structure 408 is disposed at the first end of the expandablebody and may include a permeable layer which conforms to a profile ofthe first end of the expandable body when the expandable body is in arelaxed expanded state. When in a relaxed, expanded state, theexpandable body may have a substantially spherical or globular shapewith a first end portion of the expandable body having a substantiallyhemispherical configuration. The second end portion also has a somewhatbulbous or hemispherical configuration, however, the second end portionand second ends of the struts 410 of the expandable body are not allsecured together relative to each other and each second end of thestruts of the expandable body are able to flex in a resilient mannersubstantially independent of other struts of the expandable body. Thestruts 410 of the expandable body are coupled at the first end 404 ofthe device to a hub portion or connection 412 that is disposed along alongitudinal axis of the expandable body. Each strut 410 forms a loop orleaflet portion that begins at the hub portion 412 and extends in acurving arc, which may take a spherical or bulbous shape, towards thesecond end. The struts form an apex at the second end and curves back tothe hub with a curving arc to the hub portion. Each leaflet portion ofthe expandable body portion is capable of substantially independentflexing in an inward or outward radial direction.

As discussed, embodiments of the support structure 402 may form aspherical, bulbous or globular structure including the defect spanningportion 408. Embodiments of the defect spanning structure 408 may have afirst portion with a low porosity, small pores or no porosity at all anda second portion that is fenestrated or open-celled and highly porous toblood flow. The expandable body of the support structure may includestrut members 410 made of wire or cut from sheet or tube stock as wellas other suitable materials. The surface area of the portion of devicethat is of lower or no porosity may be less than about 25% of the totalsurface area of the defect spanning structure 408. When placed in avascular defect such as a cerebral aneurysm, the higher density portionreduces the flow into the aneurysm and encourages the formation of clotand thrombus. The higher density portion may be formed by a network offibers, strands, wires or filaments. They may be on the outside, insideor integrally combined within the strut members. Preferably, the fibersare less than about 0.20 mm in diameter or thickness. Preferably thefibers are between about 10 and 100 microns. In one embodiment, they maybe formed of nanofibers. The support structure 402 may be substantiallyhollow for some embodiments.

The device 400 and expandable body thereof also have a low profileradially constrained state, as shown in FIG. 30, with an elongatedconfiguration that includes a longitudinal axis. In the collapsed,radially constrained state, the elongate flexible struts 410 of theexpandable body may be disposed substantially parallel to each other.The radial constraint on the device may be applied by an inside surfaceof the inner lumen of a microcatheter, such as the distal end portion ofthe microcatheter 110 shown in FIG. 30, or it may be applied by anyother suitable mechanism that may be released in a controllable mannerupon ejection of the device from the distal end of the catheter.

The device 400 may be deployed within a target vascular defect such thatthe defect spanning portion 408 is positioned substantially covering thedefect opening or neck of the aneurysm as shown in FIGS. 31 and 32.While the device 400 may have a substantially spherical, bulbous orglobular shape in its natural, relaxed, un-deformed or minimum energystate, the structure may be compliant to conform to various vesselanatomy; thus, the shape after implantation may have deviations from itsnatural shape. The structure may be formed from a plurality of strutmembers 410 that coalesce or are joined at one or more points. Thedevice is collapsed into a substantially linear form for deliverythrough a catheter. When released from the distal end of the catheter,the device preferably self-expands due to elastic recoil to return toits lowest energy state shape. It may form a globe-like structure thathas a generally oval, circular or ellipsoid cross-section. The distalportion that is deployed in the dome of the aneurysm may be open thusallowing at least a portion of the aneurysm to shrink after treatment.This may provide for the reduction of mass effect.

The engagement of the bulbous portion of the second end portion of thesupport structure 402 may be achieved by the exertion of an outwardradial force against tissue of the inside surface of the cavity of thepatients vascular defect. A similar outward radial force may also beapplied by the first end portion of the device so as to engage thedefect spanning structure with the inside surface or adjacent tissue ofthe vascular defect. Such forces may be exerted in some embodimentswherein the nominal outer transverse dimension or diameter of thesupport structure in the relaxed unconstrained state is larger than thenominal inner transverse dimension of the vascular defect within whichthe support structure is being deployed. The elastic resiliency of thesupport structure 402 may be achieved by an appropriate selection ofmaterials, such as superelastic alloys, including nickel titaniumalloys, stainless steel, or any other suitable material for someembodiments.

Embodiments of the permeable layer of the defect spanning structure 408may include a convex configuration that spans the first end 404 of theexpandable body in a relaxed expanded state and extends along the struts410 towards the second end 406. In some embodiments, the permeable layermay span the struts 410 towards the second end to a longitudinalposition of about 10 percent to about 60 percent the total length of theexpandable body when the expandable body is in a relaxed expanded state.Embodiments of the defect spanning structure 408 may include any of thematerials discussed above including perforated membranes, laser cutpolymer membranes, microfibers, including electrospun microfibers, aswell as others. Embodiments of the defect spanning structure may besecured to the support structure by adhesive bonding, suturing, lacing,or any other suitable method.

For some embodiments of the device, the struts 410 of the expandablebody of the support structure 402 may include perforations which areconfigured for securing the permeable layer to the expandable body bylacing, suturing or the like. The defect spanning structure 408 in theform of a permeable layer may be disposed interiorly or exteriorly to anouter surface or structure of the expandable body. The defect spanningstructure 408 may also include multiple layers. For some such multiplelayer embodiments, an outer layer of the permeable membrane, or defectspanning structure generally, disposed away from the vascular defect andtowards the patient's vasculature may include an anti-thrombogenicagent. An inner layer disposed towards the vascular defect on anopposite side of the outer layer may include a thrombogenic agent thatmay be eluted therefrom. The thrombogenic agent eluted from the innerlayer, and particularly, eluted into the vascular defect, may promotethrombosis, stabilization or healing of the vascular defect. For someembodiments, the inner layer and outer layer may be secured together ina monolithic structure. For some embodiments, the permeable layer mayinclude a thin membrane having a combination of macropores andmicropores. For some embodiments, the macropores may have a transversedimension of about 100 microns to about 500 microns and the microporeshave a transverse dimension of about 10 microns to about 100 microns.

For some embodiments, a total volume of the permeable layer of thedefect spanning structure 408 may be less than about 5 mm3. For someembodiments, a total volume of permeable layer may be between about 0.5mm3 and 4 mm3. For some embodiments, the permeable layer may have aporosity greater than about 60 percent and a thickness of less thanabout 50 microns. For some embodiments, the permeable layer may be about2 microns to about 10 microns thick. For some embodiments, theexpandable body of the support structure 402 may have a first transversedimension in a collapsed radially constrained state of about 0.2 mm toabout 2 mm and a second transverse dimension in a relaxed expanded stateof about 4 mm to about 30 mm. Some embodiments of the device 400 mayinclude a sealing member (not shown) disposed about a perimeter or othersuitable portion of the permeable layer, or defect spanning structure408 generally, and be configured to form a seal between the permeablelayer and a surface of the patient's vasculature. Some embodiments ofthe sealing member may include a swellable polymer.

Delivery systems and methods, such as an suitable delivery system ormethod discussed or incorporated herein, may be used that allows foraccurate positioning such that the device 400 is deployed within thevascular defect with the defect spanning structure 408 substantiallycovers the defect opening or neck as shown in FIGS. 31 and 32. Thedevice 400 may be implanted substantially within a target vasculardefect; however, in some embodiments, a portion of the device may extendinto the defect opening or neck or into branch vessels. Axial movementand deployment of the device 400 from the microcatheter may becontrolled by an actuator member 112 and release mechanism 114 thatreleasably secures a distal end of the actuator member to the device.The release or detachment mechanism may include any suitable embodimentof release mechanisms discussed or incorporated herein.

FIGS. 33 and 34 illustrate an embodiment of a device 420 that may havethe same or similar features, dimension and materials as those of thedevice of FIGS. 29-32. The device for treatment of a patient'svasculature 420 shown in FIG. 33 includes a substantially flattenedfirst end 422 or side of the device a support structure 424 and a defectspanning structure 426. FIG. 34 illustrates an outline of an embodimentof a device for treatment of a patient's vasculature 440 that includes atrunk portion 442 extending from a first end 444 of the device. Thetrunk portion 442 is a somewhat cylindrical extension extending from thenominal globular or spherical shape of the device. For some of theseembodiments, the detachment hub 412 may be recessed so that the profileof the device in the blood vessel lumen is reduced. The deviceembodiments 420 and 440 of FIGS. 33 and 34 may be delivered and deployedin the same manner and with any of the same devices and methods as thosediscussed above with regard to the device embodiment 400 of FIG. 29.

FIGS. 35 and 36 show an embodiment of a support structure 450 for anintrasaccular device embodiment for treatment of a patient'svasculature. The device 452 may be configured to readily conform to aninside cavity of a patient's vascular defect as shown in FIG. 37. Thedevice 452 includes the expandable body support structure 450 having alow profile radially constrained state and a relaxed expanded state. Thedevice 452 also includes a defect spanning structure 454 disposed at andconforming to a profile of a first end 456 of the expandable body 450when the expandable body is in the expanded relaxed state. The defectspanning structure 454 may Include a permeable layer.

In the radially constrained state, as shown in FIG. 38, the expandablebody 450 has an elongated tubular configuration that includes the firstend 456, a second end 458, a longitudinal axis and elongate flexiblestruts 460, portions of which are disposed substantially parallel toeach other. The first ends of the struts 460 of the expandable body 450are secured to each other in a first zig-zag shaped expandable section.The second ends of the struts 460 are secured relative to each other ina second zig-zag shaped expandable section. Both the first and secondzig-zag shaped expandable sections are disposed substantially concentricto the longitudinal axis of the expandable body 450. A middle portion462 of the expandable body has a first transverse dimension with a lowprofile suitable for delivery from a microcatheter 110.

In the expanded relaxed state, as shown in FIG. 35, the expandable body450 has an axially shortened configuration relative to the constrainedstate with second ends and the second zig-zag shaped expandable sectioneverted within a radially expanded middle portion 462 and disposedadjacent the first zig-zag shaped expandable section adjacent the firstend 456. The second zig-zag shaped expandable section is also disposedsubstantially concentric to the longitudinal axis of the expandable bodywith each strut 460 forming a smooth arc between the first and secondends 456 and 458 such that the arc of each strut extends axially outwardbeyond the first transverse dimension. Further, the middle portion 462has a second transverse dimension substantially greater than the firsttransverse dimension. In this expanded state, each strut is configuredto independently flex radially with respect to the longitudinal axis ofthe expandable body so as to readily conform to a shape of an interiorportion of a patient's vascular defect as shown in FIG. 37. When in anexpanded everted state, the support structure 450 has a distal or secondend 464 formed substantially at a distal apex of each strut 460 when thestruts 460 are in a curved arc. The struts 460 may also have a taperedouter contour 466 when in this configuration.

Delivery systems and methods, such as an suitable delivery system ormethod discussed or incorporated herein, may be used that allows foraccurate positioning and deployment of the device 452 such that thedevice is deployed within the vascular defect 106 with the defectspanning structure 454 substantially covering the defect opening or neckas shown in FIG. 37. The device 452 may be implanted substantiallywithin the vascular defect; however, in some embodiments, a portion ofthe device may extend into the defect opening or neck or into branchvessels. Axial movement and deployment of the device 452 from themicrocatheter 110 may be controlled by an actuator member 112 andrelease mechanism 114 that releasably secures a distal end of theactuator member 114 to the device 452. The release or detachmentmechanism 114 may include any suitable embodiment of release mechanismsdiscussed or incorporated herein. While disposed within themicrocatheter 110 or other suitable delivery system, as shown in FIG.38, the struts 460 may take on an elongated, non-everted configurationsubstantially parallel to each other and a longitudinal axis of thecatheter. Once the device 452 is ejected from the distal end of thecatheter 110 or the radial constraint is otherwise removed, the secondends of the struts 460 may then curve back on themselves so as to assumethe globular everted configuration within the vascular defect as shownin FIG. 37.

In a deployed expanded state, the device 452 may be configured to havean opening at the top or distal end 464 of the deployed device which mayallow for the treated aneurysm to shrink and thus reduce mass effect onsurrounding tissues as shown in FIG. 37. For these embodiments, thesupport structure sides 466 formed by the struts may be substantiallyflat or have convex surface. The distal end 464 of the device 452 may beheat treated to a shape or configuration that is substantially closedwith the inverted or everted struts making or nearly making contact. Inaddition, the distal end 464 may have an opening to allow for someaneurysm shrinkage into the cavity formed by the device during thehealing process. The proximal end 456 may be straight with a circularend, as shown in FIG. 36, or flare inward or outward to form astar-shaped proximal end opening (not shown).

In some embodiments, at least a portion of some struts 460 of thesupport structure 450 may include a plurality of holes for attachment ofthe defect spanning structure 454. In some embodiments, there may be tworows of holes in a proximal portion of some struts 460 as shown in FIG.8 discussed above. The holes may be made such that they define a lumenthat is perpendicular to the strut and the support structure 450. Thusthe axis of each hole may be disposed radially to the support structure.For some embodiments, the holes may be tangential to the struts 460 ofthe support structure. For some embodiments, the defect spanningstructure 454 may be formed by a plurality of microfibers that arethreaded through the holes of one or more support structure struts asshown in FIG. 9 discussed above. The microfibers may span from strut tostrut in a substantially straight line or have a curved shape. Thefibers may be configured so as to substantially align with the surfaceor shape defined by the support structure 450. The microfibers may beattached to the structure by knots, adhesives or a small anchor elementthat is attached to an end of a microfiber as shown in FIG. 10. For someembodiments, the fibers may have lengths configured to span a gapbetween struts and be held taught under tension when the supportstructure is in a relaxed deployed state.

Some of the microfibers may be substantially parallel to each other inthe span between two or more struts 460. The gaps or slots formed by theopenings between two adjacent fibers or microfibers may be less thanabout 0.125 mm, for some embodiments. With the microfibers beingarranged in a substantially parallel fashion as opposed to a mesh, suchas a braid or the like, a guidewire or microcatheter may be more easilypassed through the openings as shown in FIG. 11 discussed above. Thismay allow for subsequent treatment of the vascular defect. For example,subsequent treatments of the vascular defect may include the delivery ofan embolic material, devices to fill at least a portion of the spacebehind the defect spanning structure 454, both of these or any othersuitable treatment. Further, mesh structures typically involveoverlapping of fibers that result in a thicker, more voluminousmembrane, making the parallel disposition of the fibers more amendableto compaction than mesh which may be useful for achieving a low profilenecessary for delivery through a microcatheter.

In some embodiments, the defect spanning structure 454 of the device 452may include multiple layers. For some embodiments of the device, thefirst or outer layer of the defect spanning structure may be attached orsecured to the proximal or first end portion of the support structure.Subsequent or inner layer(s) may be attached distal to the proximal endof the support structure struts 460. Such a configuration is shown inFIG. 13 with some lower strut portions not shown for clarity ofillustration. In some embodiments, the fabric layer or layers may befabricated directly on to the support structure, fusing to each other,the support structure or both of these as they are formed. As discussedabove, the various layers may include bioactive agents so as to improvethe performance of some embodiments.

Embodiments of the support structure 450 may further include fixationelements, sealing members or both. Some fixation element embodiments maybe configured to extend from one or more of the support structure struts460 at or near the proximal end 456 of the device to facilitate fixationof the device within the vascular defect. Sealing member embodiments mayextend radially from the axis of the support structure or be otherwiseconfigured to engage a neck of the vascular defect as shown in FIG. 14and form a seal or reduce leakage between the defect spanning structureand tissue of the vascular defect.

Embodiments of the support structure 450 of the device for treatment ofa patient's vasculature may be fabricated from a tube of metal whereportions of the tubular structure are selectively are removed. Theremoval of material may be done by laser, electrical discharge machining(EDM), photochemical etching and traditional machining techniques aswell as any other suitable modality. In some embodiments, the supportstructure 450 may have an initial manufactured configuration that issubstantially tubular, such as the laser cut tube shown in FIG. 39. Thesupport structure may then held in a desired form or configuration forthe final implant and then heat treated to set the shape of the supportstructure 450. The structure of the expandable body may also be shapedin multiple shaping and heat treatment steps, including evertion of thedistal end 458 into the body structure of the support structure 450, asshown in the sequential steps in FIG. 40 through FIG. 42. The distal endor second end 458 may be inverted into the inside of the overall shapeto form a final tapered globular shape. For some embodiments, the distalor second end 458 is brought down to nearly the inside of the proximalor first end 456 as shown in FIG. 42. By inverting the distal end, thecurved struts that form the distal end 484 of the device 452 are easilyflexed radially providing conformance to irregular vascular defectspaces.

Embodiments of methods for fabricating vascular defect treatment deviceembodiments discussed herein may include a variety of procedures. Forsome embodiments, as discussed above, a plurality of strut members maybe formed into a substantially tubular configuration with a distal endand a proximal end where the strut members are connected at both thedistal and proximal ends. The strut array may then be shaped to form aglobular support structure. A porous membrane, mesh or microfiber matrixmay be formed that is less than about 50 microns thick for someembodiments and secured or attached to at least a portion of the supportstructure to form a defect spanning structure. For some embodiments, atube structure may be cut to form a plurality of struts that aresubstantially parallel and thus define a substantially cylindricalarray. For some embodiments, a globular support structure may be formedfrom the struts or strut array wherein one end of the tubular structureis everted so as to be disposed inside a structure envelope of the strutelements. This configuration may also be heat set for some embodiments.

Some method embodiments may include attaching the defect spanningstructure membrane, mesh or microfiber matrix to a portion of an innersurface of at least some of the support structure struts. Someembodiments may include forming a thin membrane, mesh or microfibermatrix on a three dimensional mandrel to form a three dimensional defectspanning structure. Some embodiments include perforating the thinmembrane, mesh or microfiber matrix to form a plurality of macroporesbetween about 100 microns and 500 microns in transverse dimension ordiameter. Some embodiments include casting a microfiber matrix onto aporous collector to form a defect spanning structure with bothmicropores and macropores which may optionally include flowing gas orcreating a vacuum such that gas flows through the porous collectorduring the casting process. Some embodiments include forming a porousdefect spanning structure that has a water permeability of more thanabout 2,000 mV/min/cm2 with a pressure head of 120 mmHg.

Referring to FIGS. 43 and 44, an embodiment of an intrasaccular devicefor treatment of a patient's vasculature 500 is shown that has aneverted structure at a first end and second end when in an expandedrelaxed state. The device 500, and particularly the defect spanningportion 502 of the device, may have some of the same or similarfeatures, dimensions and materials as those of the device 452 of FIG.37. The device 500 includes a support structure 504 having asubstantially closed shape with a defect spanning structure 502 disposedat a first end 506 of the device when in an expanded state. The defectspanning structure may be configured to substantially block flow intothe defect 106 or otherwise isolate the vascular defect 106 when thedevice 500 is deployed in an expanded state. The support structure 504also has a low profile radially constrained state, as shown in FIG. 44,with an elongated tubular configuration that includes a first end 508, asecond end 510, a longitudinal axis and elongate flexible struts 512disposed substantially parallel to each other between the first end andsecond end.

The first ends of the expandable body 504 are secured to a first ring orhub 514 and second ends of the expandable body are secured to a secondring or hub 516, with the first and second rings being disposedsubstantially concentric to the longitudinal axis as shown in FIG. 51. Amiddle portion of the expandable body 504 may have a first transversedimension with a low profile suitable for delivery from a microcatheter.For some embodiments, the first and second rings 514 and 516 of theexpandable member 504 may be open rings having an open lumen disposedwithin each of the first and second rings. For some embodiments, theinner lumen of the first ring 514, second ring 516 or both may be sealedor closed. Radial constraint on the device 500 may be applied by aninside surface of the inner lumen of a microcatheter, such as the distalend portion of the microcatheter 110 shown in FIG. 44, or it may beapplied by any other suitable mechanism that may be released in acontrollable manner upon ejection of the device from the distal end ofthe catheter.

The expanded relaxed state of the expandable body 504 has an axiallyshortened configuration relative to the constrained state with the firstring 514 disposed adjacent the second ring 516, both rings substantiallyconcentric to the longitudinal axis and each strut 512 forming a smootharc between the first and second rings 514 and 516 with a reverse bendat each end. A longitudinal spacing between the first ring and secondring 514 and 516 of the expandable body 504 in a deployed relaxed statemay be about 10 percent to about 50 percent of the longitudinal spacingbetween the first ring and second ring in the constrained tubular state,for some embodiments. The arc of the struts 512 between the first andsecond ends are configured such that the arc of each strut extendsaxially beyond each respective ring 514 and 516 and such that the middleportion of each strut 512 has a second transverse dimensionsubstantially greater than the first transverse dimension. Further, eachstrut 512 may be configured to independently flex radially with respectto the longitudinal axis of the expandable body. The device 500 alsoincludes a permeable layer portion of the defect spanning structure 502which is disposed at the first end 506 and conforms to a profile of afirst end 506 of the expandable body 504 when the expandable body is inthe expanded relaxed state. The permeable layer of the defect spanningstructure 502 may include a plurality of holes 518 that are configuredto produce a desired amount of permeability.

The engagement of the bulbous portion of the second end portion 520 ofthe support structure 504, when the support structure is in an expandedrelaxed state, may be achieved by the exertion of an outward radialforce against tissue of the inside surface of the cavity of thepatient's vascular defect 106. A similar outward radial force may alsobe applied by the first end portion of the device so as to engage thedefect spanning structure 502 with the inside surface or adjacent tissueof the vascular defect 106. Such forces may be exerted in someembodiments wherein the nominal outer transverse dimension or diameterof the support structure 504 in the relaxed unconstrained state islarger than the nominal inner transverse dimension of the vasculardefect 106 within which the support structure is being deployed. Theelastic resiliency of the support structure 504 may be achieved by anappropriate selection of materials, such as superelastic alloys,including nickel titanium alloys, stainless steel, or any other suitablematerial for some embodiments. For some embodiments, the expandable body504 may include a heat set shape memory material that may be heat set inthe relaxed expanded state. The expandable body may also include asuperelastic material or shape memory material such as a shape memoryalloy such as nickel titanium. Such embodiments as well as any otherembodiments of the expandable body 504 may include self-expandingembodiments.

For some embodiments, the defect spanning structure 502 may include apermeable layer of a thin membranous film or mesh which may be cast orotherwise formed onto a mandrel with a desired three dimensional shape.The three dimensionally shaped defect spanning structure may be attachedto the support structure 504 forming an umbrella-like portion as shownat the first end 506 of the device 500 in FIG. 43. The defect spanningstructure 502 may be secured to the interior, exterior or substantiallyaligned with the struts 512 of the support structure 504. In someembodiments, the defect spanning structure 502 may be disposed insidethe support structure 504 so that it is inside the support structure 504when collapsed and thus protected from abrasion and tearing duringdelivery and deployment of the device 500.

Embodiments of the permeable layer of the defect spanning structure 502may include a convex configuration that spans the first end 506 of theexpandable body 504 when the expandable body is in a relaxed expandedstate and extends along the struts towards the second end 520. In someembodiments, the permeable layer may span the struts 512 towards thesecond end 520 to a longitudinal position of about 10 percent to about60 percent the total length of the expandable body 504 when theexpandable body is in a relaxed expanded state. Embodiments of thedefect spanning structure 502 may include any of the materials discussedabove including perforated membranes, laser cut polymer membranes,microfibers, including electrospun microfibers, as well as others.Embodiments of the defect spanning structure may be secured to thesupport structure 504 by adhesive bonding, suturing, lacing, or anyother suitable method.

For some embodiments of the device 500, the struts 512 of the expandablebody of the support structure 504 may include perforations which areconfigured for securing the permeable layer to the expandable body bylacing, suturing or the like. The defect spanning structure 502 in theform of a permeable layer may be disposed interiorly or exteriorly to anouter surface or structure of the expandable body. The defect spanningstructure may also include multiple layers. For some such multiple layerembodiments, an outer layer of the permeable membrane, or defectspanning structure generally, disposed away from the vascular defect andtoward the patient's vasculature may include an anti-thrombogenic agent.An inner layer disposed towards the vascular defect 106 on an oppositeside of the outer layer may include a thrombogenic agent that may beeluted therefrom. The thrombogenic agent eluted from the inner layer,and particularly, eluted into the vascular defect, may promotethrombosis, stabilization or healing of the vascular defect. For someembodiments, the inner layer and outer layer may be secured together ina monolithic structure. For some embodiments, the permeable layer mayinclude a thin membrane having a combination of macropores andmicropores. For some embodiments, the macropores may have a transversedimension of about 100 microns to about 500 microns and the microporeshave a transverse dimension of about 10 microns to about 100 microns.

For some embodiments, a total volume of the permeable layer of thedefect spanning structure 502 may be less than about 5 mm3. For someembodiments, a total volume of permeable layer may be between about 0.5mm3 and 4 mm3. For some embodiments, the permeable layer may have aporosity greater than about 60 percent and a thickness of less thanabout 50 microns. For some embodiments, the permeable layer may be about2 microns to about 10 microns thick. For some embodiments, theexpandable body of the support structure 504 may have a first transversedimension in a collapsed radially constrained state of about 0.2 mm toabout 2 mm and a second transverse dimension in a relaxed expanded stateof about 4 mm to about 30 mm. For some embodiments, the secondtransverse dimension of the expandable body may be about 2 times toabout 150 times the first transverse dimension, more specifically, about10 times to about 20 times the first transverse dimension. Someembodiments of the device 500 may include a sealing member (not shown)disposed about a perimeter or other suitable portion of the permeablelayer, or defect spanning structure 502 generally, and be configured toform a seal between the permeable layer and a surface of the patient'svasculature. Some embodiments of the sealing member may include aswellable polymer.

For some embodiments, strut elements 512 of the expandable body may havea major transverse dimension of about 0.005 Inches to about 0.015inches, a minor transverse dimension of about 0.001 inches to about0.006 inches and a transverse cross section that is substantiallyrectangular or elliptical in shape. Strut embodiments may also have atransverse cross section includes a major transverse dimension disposedcircumferentially with respect to the longitudinal axis of theexpandable body and a minor transverse dimension disposed radially withrespect to the longitudinal axis of the occlusive body. For someembodiments, the strut members 512 may be substantially round or squarein transverse cross section with the same or similar transversedimensions as those above.

Delivery systems and methods, such as any suitable delivery system ormethod discussed or incorporated herein, may be used that allows foraccurate positioning and deployment of the device 500 such that thedevice is deployed within the vascular defect with the defect spanningstructure 502 substantially covering the defect opening or neck as shownin FIG. 43. The device 500 may be implanted substantially within thevascular defect 106, however, in some embodiments, a portion of thedevice may extend into the defect opening or neck or into branchvessels. Axial movement and deployment of the device 500 from themicrocatheter 110 may be controlled by an actuator member 112 andrelease mechanism 114 that releasably secures a distal end of theactuator member 112 to the device 500. The release or detachmentmechanism 114 may include any suitable embodiment of release mechanismsdiscussed or incorporated herein. For some embodiments, a detachmentmechanism 114, or portion thereof, may be secured within the lumen ofthe first ring 514 and seal or close the lumen of the first ring. Whiledisposed within the microcatheter or other suitable delivery system, asshown in FIG. 44, the struts 512 may take on an elongated, non-evertedconfiguration substantially parallel to each other and a longitudinalaxis of the catheter. Once the device is ejected from the distal end ofthe catheter or the radial constraint is otherwise removed, the secondends of the struts may then axially contract towards each other so as toassume the globular everted configuration within the vascular defect asshown in FIG. 43.

In use, the device shown in FIG. 43, or any other suitable deviceembodiment discussed herein, may be deployed by advancing a deliverysystem, such as the delivery system discussed above, or any othersuitable delivery system discussed or incorporated herein, to anappropriate position adjacent a vascular defect to be treated. Thedevice 500 may then be positioned within the vascular defect such as theaneurysm 106 shown in FIG. 43, and deployed such that the expandablebody 504 self-expands within the vascular defect 106 and the defectspanning structure 502 covers at least a portion of the defect openingor neck. For some embodiments, the defect spanning structure will bepositioned to cover the entire opening or neck of the defect. For someembodiments, the device is positioned within the vascular defect from aproximal end of the delivery system. The device 500 may be released ordetached from the delivery system by any suitable detachment mechanismor mechanisms including thermal, mechanical, electrolytic, shape memoryas well as any other suitable mechanism or mechanisms.

During deployment, the device 500 may be rotated in order to achieve adesired position of the device and, more specifically, a desiredposition of the defect spanning structure 502 or portions of the supportstructure 504, prior to or during deployment of the device. For someembodiments, the device 500 may be rotated about a longitudinal axis ofthe delivery system with or without the transmission or manifestation oftorque being exhibited along a middle portion of a delivery catheterbeing used for the delivery. Suitable catheters for such use have beendescribed and incorporated herein. These delivery and deployment methodsmay be used for deployment within berry aneurysms, terminal aneurysms,or any other suitable vascular defect embodiments. Some methodembodiments include deploying the device at a confluence of threevessels of the patient's vasculature that form a bifurcation such thatthe defect spanning structure substantially covers the neck of aterminal aneurysm.

For some embodiments, once the device 500 has been deployed, theattachment of platelets to the defect spanning structure 502 may beinhibited and the formation of clot within an interior space of thevascular defect 106, device, or both promoted or otherwise facilitatedwith a suitable choice of thrombogenic coatings, anti-thrombogeniccoatings or any other suitable coatings. Such a coating or coatings maybe applied either to the defect spanning structure 502 or supportstructure 504 adjacent thereto. Energy forms may also be applied throughthe delivery apparatus and/or a separate catheter to facilitate fixationand/or healing of the device adjacent the vascular defect for someembodiments. One or more embolic devices or embolic material may alsooptionally be delivered into the vascular defect 106 adjacent the defectspanning structure 502 after the device 500 has been deployed. For someembodiments, a stent or stent-like support device may be implanted ordeployed in a parent vessel adjacent the defect such that it spansacross the vascular defect prior to or after deployment of the vasculardefect treatment device.

FIGS. 45-47 illustrate an embodiment of a device for treatment of apatient's vasculature 540 that may have similar features, dimensions andmaterials to those of the device for treatment of a patient'svasculature illustrated in FIGS. 43 and 44. The device in FIG. 45includes a support structure 542 with an expandable body having anexpanded relaxed state with everted or inverted ends. The supportstructure 542 includes a plurality of struts disposed between a firsthub 544 and a second hub 546. The device 540 is shown having 8 strutsdisposed between the hubs 544 and 546, however, the embodiment 540, aswell as embodiment 500 of FIG. 43 or any other suitable embodimentdiscussed herein, may have any suitable number of struts. For example,some embodiments may have about 4 struts to about 20 struts or more.Some embodiments may have about 6 struts to about 12 struts. The strutembodiments of device 540 have a transverse cross section includes amajor transverse dimension disposed circumferentially with respect to alongitudinal axis of the support structure 542 and a minor transversedimension disposed or oriented radially with respect to the longitudinalaxis of the occlusive body. Embodiments of the expandable body may beformed from a slotted tubular member, as discussed above, with the firstend or hub 544 and second ring or hub 546 at the ends of the tubularmember shape formed or otherwise heat set in an expanded configurationwherein the first and second ends 544 and 546 are less everted than thehubs 514 and 516 of the embodiment of FIG. 43. For the device 540, someembodiments have the ends 544 and 546 of the support structure 542disposed even with or just within a plane formed by the apices of thestrut elements 548 disposed adjacent to the ends as shown in FIG. 45.The device 540 includes a defect spanning structure 549 disposed on afirst end 550 of the device 540.

Devices such as the devices of FIGS. 43 and 45, as well as any othersuitable embodiments discussed herein, may be made using a variety ofmethods. For some manufacturing embodiments, a support structure of adevice may be formed by a plurality of elongate filamentary struts thatare positioned into a substantially cylindrical circular array defininga lumen with the ends connected at one or more ends of the cylindricalarray. At least a portion of the support structure may be radiallyexpanded and heat treated to make a shape set of a radially expandedform or state. A thin membranous material formed of a biocompatiblematerial may used for a defect spanning structure in conjunction withthe support structure. For some embodiments, the defect spanningstructure may be formed in a flat pattern to allow its folded shape tosubstantially conform to at least a portion of the support structure.The defect spanning structure may also be formed in a three dimensionalconfiguration that substantially matches at least a portion of a threedimensional contour of the support structure.

For some embodiments, pores, voids, holes, or other surface features maybe made in at least a portion of the surface of the membrane of thedefect spanning structure. Such features may be formed by laser cuttingor any other suitable method and may have a substantially uniform arrayof pores. The defect spanning structure may be secured to supportstructure so as to span or cover at least a portion of one end of thesupport structure. For some embodiments, the defect spanning structuremay be secured to the support structure, at least in part, by using asilane primer and an adhesive. For some embodiments, the defect spanningstructure may be secured to an inner surface of the support structure504 so that when the device is collapsed, the defect spanning structureis housed or enclosed substantially within a lumen 560 formed by struts512 of the support structure 504, as shown in FIG. 48. Once the devicehas been made, the device may be removably secured to an elongateactuator 112 or the like of a delivery system designed for delivery ofthe device through a catheter lumen.

As discussed above, in some embodiments, the device for treatment of apatient's vasculature may Include a support structure that is formed byconnecting a plurality of wires or other elongate structures such asstrut members in a substantially parallel orientation. The strut membersmay be connected at both the distal and proximal ends to form asubstantially cylindrical structure. For some embodiments, thecylindrical structure may have a length that may be about 25 timesgreater in length than diameter. In some embodiments, a similar supportstructure may be formed by a tube 562 with longitudinal slots or cuts564 as shown in FIG. 49 thus forming an array of strut members in asubstantially cylindrical structure. The cuts or slots 564 in the tube562 may be made by laser cutting or conventional machining techniquesknown in the art of stent fabrication. A cut tube support structure maybe advantageous as it is one-piece integral structure that may notrequire any further welding or other joining techniques. For someembodiments, such a preform tube may have a length of about 5 mm toabout 50 mm, an outer diameter of about 0.4 mm to about 1 mm and a wallthickness of about 0.025 mm to about 0.1 mm. Such a tube 562 may alsoinclude holes 566 disposed through strut portions of the tube as well asloops or other connection elements 568 disposed at a first end 570 ofthe tube.

Once the longitudinal slots 564 are formed into the tube, the elongatestruts 512 formed between the longitudinal slots 564 may be shaped andheat set or otherwise set in order to produce a desired configurationfor the support structure in a relaxed deployed state. For theembodiment shown in FIG. 49, the longitudinal slots 564 are formed inthe tube which in turn forms the elongate parallel strut members 512between the slots 564. The slots 564 may also be formed such that theyterminate short of the respective ends of the tube with the first orproximal end 570, second or distal end 572 or both left in asubstantially solid tubular or cylindrical configuration with fixedinner and outer diameters or transverse dimensions. Next, the strutmembers 512 may be elastically spread apart and a shaping mandrel 574placed within an inner lumen disposed between the strut members with thestrut members 512 expanded around an outer surface of the shapingmandrel 574 as shown in FIG. 50. The shaping mandrel 574 may beconfigured to produce a globular configuration with fixed diameter ringsat the first end 570 and second end 572 and with one or both of the endsin an everted shape disposed within arced struts. Such a threedimensional shape may approximate the shape of common vascular defectssuch as saccular aneurysms. Accordingly, the support structure orexpandable body thereof may be formed into a spherical, ovoid orgenerally globular shape for some embodiments. The struts 512 may becontoured to and forced against an outer surface of the shaping mandrel574 by a variety of suitable fixtures (not shown).

The three dimensional shape of the strut members 512 and tubular endsdetermined by the shaping mandrel may be set by heat treatment as isknown in the art of vascular implant fabrication. In some embodiments,the support structure 504 may be held by a fixture configured to holdthe support structure in a desired shape and heated to about 475-525degrees C for about 5-10 minutes to shape-set the structure. For someembodiments, the support structure 504 may be shape set in two or moresteps. The final support structure shape may define a generally globularenvelop where both the distal and proximal ends lie within the envelopefor some embodiments as shown in FIG. 51. In these embodiments, thefirst and second ends 514 and 516 formed from the tube ends 570 and 572are inverted or everted so that the substantially solid tubular ends areretracted into the overall globular structure of the arced struts.

As shown, the arced portion of the struts 512 may have a sinusoldal-likeshape with a first or outer radius 576 and a second or inner radius 578near a first end of the support structure 504 of the device 500 as shownin FIG. 52. For some embodiments, the first radius 576 and second radius578 of the support structure 504 may be between about 0.12 mm to about 3mm. In some embodiments, the outer first radius may be larger than theinner second radius. The ratio of the inner to outer radius may bebetween about 20% and 60%. For some embodiments, the distance betweenthe first end 514 and second end 516 may be less than about 60% of theoverall length of the support structure 504 for some embodiments. Asmall gap between the rings 514 and 516 at the first end and second endallows for the distal or second end ring 516 to flex downward toward theproximal or first end ring 514 when the device meets resistance at thedistal end and thus provides longitudinal conformance. The strutsmembers 512 may be shaped such that there are no portions that arewithout curvature over a distance of more than about 2 millimeters.Thus, for some embodiments, each strut 512 may have a substantiallycontinuous curvature. This substantially continuous curvature mayprovide smooth deployment and may reduce the risk of vessel perforation.For some embodiments, the second end 516 may be retracted or everted toa greater extent than the first end 514 such that the second end portion520 of the support structure or device generally may be more radiallyconformal than the first end portion. Conformability of a distal orsecond end portion directed toward the interior of a vascular defectwhen deployed may provide better device conformance to Irregular shapedaneurysms or other vascular defects, such as defects 106 or 210.

Some defect spanning structure embodiments for the devices of FIGS. 43,45, or any other suitable embodiment discussed herein may include a thinmetallic film. The metallic film thickness may be between 0.0015 and0.015 mm in some cases. The thin metallic film may be made by rolling,physical or chemical vapor deposition (PVD or CVD) also known assputtering and other means known in the art of metallic filmfabrication. Sputter deposition of nickel-titanium or nitinol may bedone at a low pressure, preferably less than about 10-8 torr. A mandrel600, made in the shape of the desired film as shown in FIG. 53, may beused as a target for the deposition. Optionally, this same mandrel maybe used for dipping, spraying or other processes for the formation ofpolymeric membranes described herein. The metallic film 602, shown inFIG. 54, may be deposited on to the mandrel 600 and then removed forattachment to a support structure, such as support structure embodiment542 shown in FIG. 45. The mandrel 600 may have a handle 604 that may beused to hold the mandrel. The mandrel may also have a depression 606 inone end to form a recessed end of the device or expandable body thereof.The mandrel 600 and thus the film 602 formed thereon may have panels 608so that the film spans a gap between the support structure struts in asubstantially straight line. The resulting shape may be somewhat like anumbrella or umbrella-like in shape with panels as shown in FIG. 54. Thefilm 602 may also have holes or perforations 610 disposed therein toprovide a desired level of permeability.

The thin film defect spanning structure 600 may be made at least in partof nitinol. CVD fabrication of thin film nitinol membranes is describedby Desatnik et al. in U.S. Patent Application No. US2007/0061006, filedSep. 14, 2005, titled Methods of Making Shape Memory Films by ChemicalVapor Deposition and Shape Memory Devices Made Thereby, which isincorporated by reference herein in its entirety. Metallic filmembodiments may be sputtered on to a mandrel 600 or target that has atemperature greater than about 400° C. as described by Ho et al. in U.S.Pat. No. 6,689,486, filed Oct. 28, 2002, titled Bimorphic,Compositionally-Graded, Sputter-Deposited, Thin Film Shape MemoryDevice, which is incorporated by reference herein in its entirety. Insome embodiments, metallic thin film embodiments may be sputtereddirectly on to the struts 512 of the support structure 504 by placingthe support structure over a mandrel thus eliminating the need to make aseparate attachment step. The mandrel 600 may be pivoted or angledwithin a CVD chamber to coat the sides that are substantiallynon-orthogonal to the sputter stream 612 as shown in FIG. 55.

Some defect spanning structure embodiments may include two or morelayers. A two-layer structure may be attached or secured to supportstructure struts 512 by adhering the two layers to themselves onopposing sides of each strut 512. For example, a first layer 620 maycover an outer surface of at least a portion of a support structurestrut 512 and a second layer 622 may cover at least a portion of theinner surface of the strut as shown in the embodiment illustrated inFIG. 56. Thus, the support structure struts 512 may be trapped, capturedor otherwise encapsulated by the first and second layers 620 and 622without being physically bonded or fused to the defect spanningstructure. This configuration may be desirable if the support structure504 is made of a material such as nitinol that may be difficult to bondwith other materials. Further, the attachment may be accomplishedwithout significant heating of the support structure. For someembodiments, significant heating of the support structure 504 may havean undesirable affect on its mechanical characteristics.

For some embodiments, a thin permeable membrane may be secured to asupport structure embodiment by adhesive bonding using a biocompatibleadhesive. Adhesives such as ultraviolet (UV) cured or visible lightcured adhesives may be used in some cases. For such embodiments theadhesive bonding process may involve the use of a primer material inorder to improve the adherence or bonding process. For some embodiments,a binding agent or primer material may be applied to the supportstructure or polymer membrane adjacent the support structure prior toapplying the adhesive to the membrane or support structure. Someexamples of adhesives that may be used to secure the membrane to asupport structure include Dymax 1000 series adhesives, Loctite 3200,3300 and 3900 series adhesives as well as others. Some suitable primermaterial embodiments may include gammamethacryloxypropyltrimethoxysilane (g-MPTS) a monofunctional silane,vinyltriethoxysilane, bis(3-trimethoxysilyl)propyletylenediamine,tris(3-trimethoxysilylpropyl)isocyanurate, or any other suitable primermaterial depending on the application and polymer membrane material.Either or both of the adhesive and primers may be applied by spraying,wiping, dipping or any other suitable application technique. For someembodiments, it may be desirable to apply the adhesive, primer or bothin a thin even coat prior to the adhesive bonding process.

In some embodiments, a membrane 630 of a defect spanning structure 502may be fabricated in a flat pattern from a film or sheet of material andthen folded, thermoformed, vacuum-formed or otherwise reshaped to form adesired three dimensional shape approximating the shape of the supportstructure portion to which it will be secured. For some embodiments, theflat pattern of the membrane 630 may have a central portion 632 that issubstantially circular with a plurality of panels 634 that extendradially as shown in FIG. 57. Holes (not shown) may be formed in theflat pattern by laser perforation, mechanical perforation, photochemicaletching (PCM) or any other suitable method.

For some embodiments, a defect spanning structure 502 may be fabricatedwith holes 640 to facilitate attachment to struts 512 or other portionsof support structure embodiments. Struts 512 or other projections of thesupport structure may be threaded through the holes 640, as shown inFIG. 58, so that when the support structure 504 is allowed to expand toits globular configuration, it opens the defect spanning structure 502with it. As such, a single layer of membrane may be disposed on bothsides of the support structure 502. For some embodiments, the supportstructure struts 512 may have slots, grooves, holes 650 or otherfeatures for receiving a portion of the defect spanning structure 502 orotherwise facilitate attachment as shown in FIG. 59.

In any of the described embodiments, the device, such as device 540, maybe used to treat various vascular defects or sites including bloodvessels, cerebral and peripheral aneurysms, fistula and other vascularconditions where occlusion is desired. An example of a terminal aneurysm210 is shown in FIG. 60 in section. For some deployment embodiments, oneor more elongate access instrument(s) such as canula, catheters,guidewires and the like may be use to facilitate placement of the device540. The tip of a catheter, such as a microcatheter 110 may be advancedinto or adjacent the vascular site (e.g., aneurysm 210) as shown in FIG.61. For some embodiments, an embolic coil or other vaso-occlusive device(not shown) may be placed within the aneurysm 210 to provide a frameworkfor receiving the device 540. In addition, a stent may be placed withina parent vessel of the aneurysm 210 substantially crossing the aneurysmneck prior to or during delivery of devices for treatment of a patient'svasculature discussed herein. For some embodiments, a device 540,attached to an elongate actuator 112 of a delivery apparatus may beinserted within or adjacent an access instrument that may include amicro-catheter 110.

The device 540 may be inserted through a microcatheter 110 such that thecatheter lumen restrains radial expansion of the device 540 duringdelivery. Once the distal tip or deployment port of the delivery systemis positioned in a desirable location adjacent or within a vasculardefect 210, the device 540 may be deployed out the distal end of thecatheter thus allowing the device to begin to radially expand as shownin FIG. 62. As the device 540 emerges from the distal end of thedelivery system, the device 540 expands to an expanded state within thevascular site, but may be at least partially constrained by an interiorsurface of the vascular defect 210. Radial expansion of the device 540may serve to secure the device within the vascular defect 210 and alsodeploy the defect spanning structure across at least a portion of anopening (e.g., aneurysm neck) so as to at least partially isolate thevascular defect 210 from flow, pressure or both of the patient'svasculature adjacent the vascular defect as shown in FIG. 63. For someembodiments, once deployed, the defect spanning structure maysubstantially slow flow into the vascular site.

For some embodiments, the device may be manipulated by the user toposition the device within the vascular site during or after deployment.Markers, such as radiopaque markers, on the device or delivery systemmay be used in conjunction with external imaging equipment (e.g., x-ray)to facilitate positioning of the device or delivery system duringdeployment. Once the device is properly positioned, the device may bedetached by the user. For some embodiments, the detachment of the devicefrom the elongate actuator of the delivery system may be affected by thedelivery of energy (e.g., heat, radiofrequency, ultrasound, vibrational,or laser) to a junction or release mechanism between the device and thedelivery apparatus. Once the device has been detached, the deliveryapparatus may be withdrawn from the patients vasculature or patientsbody. For some embodiments, a stent may be place within the parentvessel substantially crossing the aneurysm neck after delivery of thedevice.

For some embodiments, a biologically active agent or a passivetherapeutic agent may be released from a responsive material componentof the device. The agent release may be affected by one or more of thebody's environmental parameters or energy may be delivered (from aninternal or external source) to the device. Hemostasis may occur withinthe vascular defect as a result of the isolation of the vascular defect,ultimately leading to clotting and substantial occlusion of the vascularsite by a combination of thrombotic material and the device. For someembodiments, thrombosis within the vascular site may be facilitated byagents released from the device and/or drugs or other therapeutic agentsdelivered to the patient.

Embodiments herein are directed to positioning and delivery of medicaldevices including methods and devices for the positioning and deliveryof devices into luminal organs such as blood vessels. Some embodimentsmay be used in a variety of luminal body organs or spaces, includingembodiments directed to treatment for vascular lesions and defects suchas aneurysms. Some embodiments may be particularly useful for vascularnavigation and the treatment of vascular defects including aneurysms andmore particularly cerebral aneurysms. The devices may also be useful forpositioning of a stent that is configured for use at a vesselbifurcation. The apparatus may also find use in the positioning of drugdelivery devices so as to allow the delivery of therapeutic agent(s) ata selected site within or about a luminal organ. The devices may also beuseful for positioning a needle, cutting element or other surgicalinstrument at the desired rotational position within a luminal organ.Some delivery system embodiments may be configured for the positioningof medical instrumentation and devices within luminal organs. Someembodiments may be useful for positioning a variety of medicalinstruments, implants, drug delivery devices and diagnostic devices.

Referring to FIG. 64, some delivery catheter embodiments 700 include aflexible, elongate member with a proximal end 702 which may include ahub or handle, an intermediate portion or shaft 704 and a rotationallypositionable or rotatable distal end 706 that may be configured for usewith existing surgical and vascular access catheters, introducers,microcatheters, guidewires, cannula and other elongate medicalinstruments. In some embodiments, rotation of the rotatable distal end706 may be accomplished without transmission of torque throughout alength of the apparatus 700 and without rotation of an outer surface ofthe length or intermediate portion 704 of the delivery catheter 700. Forsome embodiments, there is no rotation, rotating elements or torquetransmission in the intermediate portion 704 between the proximal end702 the rotatable distal end 706. Thus, rotation of the distal end 706is accomplished without the transmission of torque along the length ofthe catheter 700.

In some embodiments, the catheter 700 may be configured to be advancedthrough a catheter such as a guide catheter for the rotationalpositioning of medical devices or instruments within the vasculature forthe treatment of focal lesions or defects. The delivery catheter 700 andimplant device may be configured to be delivered through the lumen of amicrocatheter, known in the art of neurovascular navigation and therapy.Focal lesions or defects such as aneurysms often lie along one side of ablood vessel wall. The rotatable distal end 706 may rotate relative toand substantially independent of the rest of the positioning catheter asshown in FIG. 64. Accordingly, some catheter embodiments may provide auser with the ability to position a medical device with a portion orperipheral region 708 with diagnostic or therapeutic capability in thedesired rotation position or circumferential relationship to the targetsite, lesion or defect 710 of a patient's vasculature 712 as shown inFIG. 65.

The rotatable distal end 706 may be freely rotating like a bearing or itmay be driven by another member or mechanism within the apparatus. Thedrive mechanism may be housed distally near the rotatable distal end 706or at some position toward the proximal end 702 and connected to therotatable distal end by a connecting member. For some embodiments, therotatable distal end 706 may be driven by an electro-mechanicalmechanism, electro-magnetic mechanism (e.g., micromotor), push rod andscrew mechanism, shape-memory coil mechanism, hydraulic mechanism,multi-layered torque cable mechanism or other flexible torquetransmission mechanism. The drive mechanism may allow for slow,continuous rotation or controlled rotation in increments of less thanabout 45° and more preferably less than about 30°.

Referring to FIG. 66, for some embodiments, the delivery catheter mayinclude a multi-layered torque cable (MLTC) mechanism 714 fortransmission of torsion through the apparatus in a flexible structure.The MLTC mechanism may include one or more tubular layers of coiled orbraided wire. The MLTC mechanism may have at least one inner layer 716and an inner layer comprising a multi-stranded or multifilar structure.In some embodiments, the inner layer 716 includes a coil and the outerlayer 718 includes a multi-stranded braid as shown in FIG. 66. An outerpolymer layer 720 may also be disposed over the inner and outer layers716 and 718 of the mechanism 714. Other multi-layered torque cablemechanisms are described in U.S. Pat. No. 5,154,705 to Fleischhacker etal., titled Hollow lumen cable apparatus, filed Jul. 24, 1989 and U.S.Pat. No. 5,165,421 to Fleischhacker et al., titled Hollow lumen cableapparatus, filed Jul. 20, 1990, which are herein incorporated in theirentirety by reference.

For some embodiments, the delivery catheter may include a flexible,hollow elongate member (e.g., catheter) with a rotatable distal endmember. A medical device that is attached to a flexible, elongatedelivery member may be advanced inside the catheter in a substantiallyco-axial arrangement until the medical device is at least partiallywithin the rotatable distal end member. The delivery catheter mayinclude a transmission member for the transmission of force or energy tothe distal end. When force and or energy is delivered through thetransmission member, the force or energy is converted to torque which isdelivered to the medical device thus rotation of the rotatable distalend of the delivery catheter.

For some embodiments, a delivery catheter 724 may include a micromotorwhich is coupled to a rotatable distal end 728 and provided an energysource by energy transmission members such as electrical wires 730 orthe like. The micromotor may be part of the proximal hub, shaft ordistal end. The micromotor 726 may be at or proximate the distal end 728as shown in FIG. 67. The micromotor 726 may be fabricated usingmicro-electromechanical (MEMS) manufacturing techniques and may beelectromagnetic, piezoelectric, hydraulic or other type known in the artof micromotors. A MEMS motor may be constructed with an outer ring andreciprocating shuttle similar to that described by Allen et al. inMicromachine Wedge Stepping Motor, 1998 ASME International MechanicalEngineering Congress, Anaheim, Calif. The micromotor may include a leadscrew which rotates due to ultrasonic vibrations as described in U.S.Pat. No. 6,940,209 to Henderson, titled Ultrasonic lead screw motor,filed Sep. 8, 2003, which is herein incorporated in its entirety byreference.

For some embodiments, a delivery catheter having a rotatable distal endmay include a stored energy member such as a spring. The stored energymember may be a linear spring, torsion spring, or leaf spring. Therelease of energy stored by the spring may be activated upon retractionof a restraining member that prevents rotation of the rotationallypositionable distal. Multiple restraining members may be used to allowseveral incremental rotations. Alternatively, several springs may beused in combination. In one embodiment, a torsional spring stored energymember is attached to the rotationally positionable distal member. Oneor more retractable restraining members are positioned to engage thetorsional spring member.

Referring to FIGS. 68-70A, for some embodiments, a delivery catheterhaving a rotatable distal end 740 may include a push/pull rod 742 andscrew mechanism 744 that converts linear force to and/or from rotationforce. The threads of the screw mechanism may have a helix angle that isgreater than or equal to 45 degrees. The included angle of the teeth maybe about 29 degrees to about 60 degrees. For such embodiments, aproximal portion 746 of the mechanism may convert rotation force tolinear force at the proximal end thus advancing and retracting apush/pull rod member 742 within a lumen of the elongate deliveryapparatus 740. The mechanism may include an internally threaded member748 and an externally threaded member 750 as shown in FIG. 68. Anexternal rotating member 752 may also be disposed at the proximalportion 746 which is configured to impart relative rotational motion. Atthe distal end 754 of the delivery catheter 740, the linear force isconverted back to rotational force with a similar mechanism thusrotating the rotatable distal member as shown in FIG. 69. As shown inFIG. 69, a flexible outer shaft 756 is disposed about a shaft having anexternally threaded member 758 which is coupled to an internallythreaded member 760 with the two threaded members in threadedengagement. Thus, torsion is not transmitted through the majority of theapparatus.

The conversion of torque may also be accomplished with a slotted tube762 as shown in FIGS. 70 and 70A. For this embodiment, a push/pull shaft764 having a radially extending pin 766 is disposed within the rotatableslotted tube 762. The pin 766 is slidingly engaged with the slot 768 ofthe slotted tube. The slotted tube is configured to be coupled to theshaft 770 of the catheter so as to allow rotation but not axialtranslation. The push/pull shaft is configured to be axially translatedwithout rotation. Thus, axial translation of the push/pull shaft 764relative to the rotatable slotted tube 762 generates rotational movementbetween the slotted tube 762 and the catheter body and push/pull shaft764. A release mechanism 772 may be disposed at a distal end of theslotted tube 762.

Referring to FIG. 71, some embodiments, a delivery catheter 780 with arotatable distal end 782 may include a fluid actuated member ormechanism that rotates in response to a fluid force. The fluid actuatedmember may be part of or attached to the rotationally positionabledistal end. The apparatus also has a fluid path 784 that allows for theinjection of a fluid to apply pressure on the fluid actuated member. Thefluid actuated member may include one or more surfaces, blades orelements 786 that are angulated relative to the fluid path. The fluidactuated member may include a microturbine for some embodiments.Optionally, the injected fluid also provides lubrication of therotationally positionable distal end. The injected fluid may be abiocompatible fluid such as sterile saline and may exit the apparatuswithin the body. Alternatively, the fluid path may describe a closedcircuit and the fluid may pass through the fluid actuated member andthen return to exit the apparatus outside the body. The term fluid asused herein with regard to the delivery system embodiments should beinterpreted broadly as any liquid, gas or emulsion that can readily flowthrough a small catheter lumen, A push/pull shaft 788 may be secured toa device for treatment of a patients vasculature disposed at a distalend of the catheter 780.

Referring to FIG. 72, some embodiments of a delivery catheter 790 havinga rotatable distal end 791 may Include an energy responsive material(ERM) member 792 that responds to the input of energy by increasing ordecreasing in length. The ERM member 792 may be configured in a way sothat rotation is created when it increases in length. One suchconfiguration is a helix or coil. The ERM coil 792 may be in the distalsection 794 of the delivery catheter 790. A second helical or threadedguide member either inside or outside the ERM coil 792 and a restrainingmember 795 may be used to prevent an expansion ERM coil that would forcethe ERM coil to rotate. An external coil or internally threaded tubecould provide both guide member and restraining member functions.Alternatively, a proximal stop 796 and external restraining tube canforce rotation of the coil as shown by arrows 798 in FIG. 72. As energyis delivered to the ERM coil, the ERM coil changes in length and thus isforced to rotate within or about the guide member due to restraint bythe restraining member and in turn, rotates the distal end 791 asindicated by arrows 800. The coil of ERM may be made of anickel-titanium alloy commonly known as Nitinol, shape memory polymersor other ERMs known in the art. The nitinol ERM coil may be heat treatedto have an austenite finish temperature (Af) greater than about 25degrees Celsius. A potentially suitable material is commerciallyavailable from Dynalloy, Inc. under the tradename Flexinol®.

The delivery catheter embodiments may include a release mechanism totemporarily retain and or connect to a device such as any of the devicesfor treatment of a patient's vasculature discussed herein. In addition,the release mechanism may include any of the release mechanismembodiments discussed herein, such as a thermal mechanism, electrolyticmechanism, hydraulic mechanism, shape memory material mechanism, or anyother mechanism known in the art of endovascular implant deployment.Some delivery catheter embodiments may be made of various biomaterialsknown in the art of implant devices including but not limited topolymers, metals, and composites thereof. Suitable polymers includeacrylics, polyurethanes, silicones, polypropylene, polyvinyl alcohol,polyesters (e.g., polyethylene terephthalate or PET) and PolyEtherEtherKetone (PEEK). Suitable metals include cobalt-chrome alloys,nickel-titanium alloys (e.g., nitinol), zirconium-based alloys,platinum, stainless steel, titanium, gold, and tungsten. Optionally, theapparatus may comprise wires, fibers or strands that are coiled, woven,or braided as is known in the art of reinforced medical catheters.Optionally, the apparatus may be coated with various polymers to enhancelubricity or other performance characteristics.

In any of the previously described rotatable delivery catheterembodiments, the rotatable distal end member may further comprise aratcheting mechanism to provide indexing of the rotation and thusgreater control over the amount of rotation by the user. The ratchetingmechanism may be at the proximal interface of the rotatable distal endand a flexible elongate member (e.g., catheter) so that as the rotatabledistal end rotates, it preferentially seeks discrete rotationalpositions. The ratcheting mechanism may be configured to provide atleast 4 and more preferably at least 6 discrete rotational positionswithin 360°.

Some method embodiments for positioning medical devices or instrumentswithin luminal organs may include inserting a vascular access apparatusor system including a guidewire, catheter or both to a positionproximate a vascular defect. A luminal implant device that is releasablyconnected to an elgongate delivery member having a rotatable distalmember may then be disposed within or about the vascular accessapparatus. The implant device may be positioned proximate a focallesion, defect or treatment site and the rotatable distal member and theimplant device rotated to achieve a desired angular orientation. Theimplant device may then be released from the elongate delivery member.For some embodiments, the method may include providing a medical devicefor treatment of a patient's vasculature having a peripheral region withdiagnostic or therapeutic capability attached to a flexible, elongateendoluminal delivery catheter with a proximal end and a rotationallypositionable distal end. The method may also include advancing theendoluminal delivery catheter within or about a vascular access devicehaving a catheter, guidewire, or combination thereof. The medical devicemay then be rotationally positioned such that the peripheral region ispositioned adjacent a target site within or about a luminal organ. Someof the method embodiments may further include delivering force or energythrough the elongate delivery apparatus or catheter in order to activatean energy responsive material, motor, or mechanism to effect rotation ofthe rotable distal member, rotating the implant device within theluminal organ such that a specific portion of its periphery ispositioned over or adjacent a lesion, defect or target treatment site,positioning an implant device such that a portion of it spans a bloodvessel opening or defect, advancing a push member through a lumen of theelongate delivery apparatus to effect rotation of the rotatable distalmember, or heating a portion of the delivery apparatus to effectrotation of the rotatable distal member.

With regard to the above detailed description, like reference numeralsused therein refer to like elements that may have the same or similardimensions, materials and configurations. While particular forms ofembodiments have been illustrated and described, it will be apparentthat various modifications can be made without departing from the spiritand scope of the embodiments of the invention. Accordingly, it is notintended that the invention be limited by the forgoing detaileddescription.

What is claimed is:
 1. A device for treatment of a patient's vasculaturecomprising: a first hub; a second hub; a support structure having alongitudinal axis and disposed between the first hub and the second hub,the support structure including a plurality of struts; and a layer ofmaterial disposed over the plurality of struts, wherein the supportstructure has a low profile, radially constrained state with anelongated tubular configuration having a transverse dimension, theradially constrained state having a low profile suitable for deliveryfrom a microcatheter, and wherein the support structure also has anexpanded state having a first end, a second end, and a smooth outersurface and having an axially shortened configuration relative to theradially constrained state.
 2. The device of claim 1, wherein the layerof material comprises at least one of acrylic, silk, silicone, polyvinylalcohol, polypropylene, polyester, PolyEtherEther Ketone (PEEK),polytetrafluoroethylene (PTFE), polycarbonate urethane (PCU) andpolyurethane (PU).
 3. The device of claim 1, wherein the layer ofmaterial comprises polytetrafluoroethylene (PTFE).
 4. The device ofclaim 1, wherein the support structure is formed from a slotted tubularmember.
 5. The device of claim 1, wherein the support structurecomprises between about 4 struts and about 20 struts.
 6. The device ofclaim 1, wherein the support structure comprises between about 6 strutsand about 12 struts.
 7. The device of claim 1, wherein the supportstructure comprises 8 struts.
 8. The device of claim 1, wherein 8 strutsextend from at least one of the first hub and the second hub.
 9. Thedevice of claim 1, wherein the plurality of struts of the supportstructure in its radially constrained state comprises a circumferentialarray of struts numbered between about 4 and about
 20. 10. The device ofclaim 1, wherein the plurality of struts of the support structure in itsradially constrained state comprises a circumferential array of strutsnumbered between about 6 and about
 12. 11. The device of claim 1,wherein the plurality of struts of the support structure in its radiallyconstrained state comprises a circumferential array of 8 struts.
 12. Thedevice of claim 1, wherein at least one of the first or second ends isinverted.
 13. The device of claim 1, wherein the plurality of strutsincludes struts having a transverse cross section including a majortransverse dimension disposed circumferentially with respect to thelongitudinal axis of the support structure and a minor transversedimension disposed radially with respect to the longitudinal axis of thesupport structure.
 14. The device of claim 1, wherein the supportstructure has a three dimensional contour, and wherein the layer ofmaterial has a three dimensional configuration that substantiallymatches at least a portion of the three dimensional contour of thesupport structure.
 15. The device of claim 1, wherein the layer ofmaterial is secured to the support structure at least in part by anadhesive.
 16. The device of claim 1, wherein the layer of materialcovers at least a portion of the first or second ends of the supportstructure.
 17. The device of claim 1, wherein the layer of materialincludes pores.
 18. The device of claim 1, wherein the expanded state ofthe support structure is a heat-formed three-dimensional shape.
 19. Thedevice of claim 1, wherein the layer of material is stretched betweenadjacent struts of the plurality of struts when the support structure isin the expanded state.
 20. The device of claim 1, wherein each strut ofthe plurality of struts extends from the first hub to the second hub.